Cellulose esters in highly-filled elastomeric systems

ABSTRACT

An elastomeric composition is provided comprising at least one non-fibril cellulose ester, at least one non-nitrile primary elastomer, optionally a starch, and at least 70 parts per hundred rubber (phr) of one or more fillers, wherein the weight ratio of the cellulose ester to the starch is at least 3:1, wherein the cellulose ester is in the form of particles having an average diameter of not more than 10 μm.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.Nos. 61/567,948, 61/567,950, 61/567,951, and 61/567,953 filed on Dec. 7,2011, the disclosures of which are incorporated herein by reference tothe extent they do not contradict the statements herein.

FIELD OF THE INVENTION

The present invention relates generally to elastomeric compositionscomprising a cellulose ester and to processes for making suchelastomeric compositions.

BACKGROUND OF THE INVENTION

Elastomeric compositions comprising high amounts of filler are utilizedin various applications, such as in tires, where increased elasticity,hardness, tear resistance, and stiffness are desired. These enhancedproperties are generally achieved by adding large amounts of hardfillers (e.g., carbon black, silica, and other minerals) to theelastomeric composition. An additional benefit of highly-filledcompositions is that they can be produced on a more economic scalecompared to elastomeric compositions containing little or no fillers.The elastomer components are generally the most expensive component inan elastomeric composition, thus the utilization of high amounts offiller can minimize the amount of expensive elastomer used in theelastomeric composition.

Unfortunately, the presence of high amounts of fillers in an elastomericcomposition greatly increases the processing viscosity of thecomposition, thus making it very difficult to process. One currentsolution to this problem is to add a processing aid, such as an aromaticprocessing oil, to the elastomeric composition in order to reduce itsprocessing viscosity. However, the incorporation of processing aids intothe elastomeric compositions generally softens the cured elastomericcompositions, thereby mitigating the desired benefits of adding highamounts of filler to the composition.

Accordingly, there is a need for a highly-filled elastomeric compositionthat is both easily processable and that exhibits ideal elasticity,hardness, tear resistance, and stiffness when cured. In addition, thereis a need for a processing aid for elastomeric compositions that canimprove the processability of the elastomeric composition and alsoenhance its elasticity, hardness, tear resistance, and/or stiffness.

BRIEF SUMMARY OF THE INVENTION

In one embodiment of the present invention, an elastomeric compositionis provided that comprises at least one non-fibril cellulose ester, atleast one non-nitrile primary elastomer, optionally a starch, and atleast about 70 parts per hundred rubber (phr) of one or more fillers.The ratio of cellulose ester to starch in the composition is at leastabout 3:1. Further, the cellulose ester is in the form of particleshaving an average diameter of less than about 10 μm.

In another embodiment of the present invention, an elastomericcomposition is provided comprising at least one primary elastomer, oneor more fillers, and at least one non-fibril cellulose ester. Theelastomeric composition exhibits a dynamic mechanical analysis (DMA)strain sweep modulus as measured at 5% strain and 30° C. of at least1,450,000 Pa and a molded groove tear as measured according to ASTM D624of at least about 125 lbf/in.

In yet another embodiment of the present invention, a process forproducing an elastomeric composition is provided. The process comprisesblending at least one cellulose ester, at least one non-nitrile primaryelastomer, and at least 70 phr of one or more fillers at a temperaturethat exceeds the Tg of the cellulose ester to produce an elastomericcomposition. The newly-produced elastomeric composition exhibits aMooney viscosity at 100° C. as measured according to ASTM D1646 of notmore than about 110 AU.

In a further embodiment of the present invention, a process to producean elastomeric composition is provided. The process comprises blendingat least one cellulose ester, at least one primary elastomer, and one ormore fillers at a temperature that exceeds the Tg of the cellulose esterto produce an uncured elastomeric composition; and curing the uncuredelastomeric composition to produce a cured elastomeric composition. Theuncured elastomeric composition exhibits a Mooney viscosity as measuredaccording to ASTM D1646 of not more than about 110 AU. Furthermore, thecured elastomeric composition exhibits a dynamic mechanical analysis(DMA) strain sweep modulus as measured at 5% strain and 30° C. of atleast 1,450,000 Pa and a molded groove tear as measured according toASTM D624 of at least about 120 lbf/in.

Other inventions concerning the use of cellulose esters in elastomershave been filed in original applications by Eastman Chemical Company onNov. 30, 2012 entitled “Cellulose Esters in Pneumatic Tires”, “CelluloseEster Elastomer Compositions”, and “Process for Dispersing CelluloseEsters into Elastomeric Compositions; the disclosures of which arehereby incorporated by reference to the extent that they do notcontradict the statements herein.

DETAILED DESCRIPTION

This invention relates generally to the dispersion of cellulose estersinto elastomeric compositions in order to improve the mechanical andphysical properties of the elastomeric composition. It has been observedthat cellulose esters can provide a dual functionality when utilized inelastomeric compositions and their production. For instance, celluloseesters can act as a processing aid since they can melt and flow atelastomer processing temperatures, thereby breaking down into smallerparticles and reducing the viscosity of the composition duringprocessing. After being dispersed throughout the elastomericcomposition, the cellulose esters can re-solidify upon cooling and canact as a reinforcing filler that strengthens the composition.

In certain embodiments of this invention, a highly-filled elastomericcomposition is provided that comprises high amounts of one or morefillers. Highly-filled elastomeric compositions are desirable forvarious applications where modulus, strength, and elasticity arenecessary. Unfortunately, it has been observed that adding high amountsof filler to an elastomeric composition makes subsequent processing ofthe elastomeric composition very difficult due to the increasedviscosity of the composition. However, the addition of cellulose estersto the elastomeric composition can remedy many of the deficienciesexhibited by conventional highly-filled elastomeric compositions. Thus,in certain embodiments of the present invention, cellulose esters canenable the production of highly-filled elastomeric compositionsexhibiting superior viscosity during processing and enhanced modulus,stiffness, hardness, and tear properties during use.

In certain embodiments of this invention, an elastomeric composition isprovided that comprises at least one cellulose ester, at least oneprimary elastomer, optionally, one or more fillers, and, optionally, oneor more additives.

(A) Cellulose Esters

The elastomeric composition of the present invention can comprise atleast about 1, 2, 3, 4, 5, or 10 parts per hundred rubber (“phr”) of atleast one cellulose ester, based on the total weight of the elastomers.Additionally or alternatively, the elastomeric composition of thepresent invention can comprise not more than about 75, 50, 40, 30, or 20phr of at least one cellulose ester, based on the total weight of theelastomers. The term “phr,” as used herein, refers to parts of arespective material per 100 parts by weight of rubber or elastomer.

The cellulose ester utilized in this invention can be any that is knownin the art. The cellulose esters useful in the present invention can beprepared using techniques known in the art or can be commerciallyobtained, e.g., from Eastman Chemical Company, Kingsport, Tenn., U.S.A.

The cellulose esters of the present invention generally compriserepeating units of the structure:

wherein R¹, R², and R³ may be selected independently from the groupconsisting of hydrogen or a straight chain alkanoyl having from 2 to 10carbon atoms. For cellulose esters, the substitution level is usuallyexpressed in terms of degree of substitution (“DS”), which is theaverage number of substitutents per anhydroglucose unit (“AGU”).Generally, conventional cellulose contains three hydroxyl groups per AGUthat can be substituted; therefore, the DS can have a value between zeroand three. Alternatively, lower molecular weight cellulose mixed esterscan have a total degree of substitution ranging from about 3.08 to about3.5. Generally, cellulose is a large polysaccharide with a degree ofpolymerization from 700 to 2,000 and a maximum DS of 3.0. However, asthe degree of polymerization is lowered, as in low molecular weightcellulose mixed esters, the end groups of the polysaccharide backbonebecome relatively more significant, thereby resulting in a DS rangingfrom about 3.08 to about 3.5.

Because DS is a statistical mean value, a value of 1 does not assurethat every AGU has a single substituent. In some cases, there can beunsubstituted AGUs, some with two substitutents, and some with threesubstitutents. The “total DS” is defined as the average number ofsubstitutents per AGU. In one embodiment of the invention, the celluloseesters can have a total DS per AGU (DS/AGU) of at least about 0.5, 0.8,1.2, 1.5, or 1.7. Additionally or alternatively, the cellulose esterscan have a total DS/AGU of not more than about 3.0, 2.9, 2.8, or 2.7.The DS/AGU can also refer to a particular substituent, such as, forexample, hydroxyl, acetyl, butyryl, or propionyl. For instance, acellulose acetate can have a total DS/AGU for acetyl of about 2.0 toabout 2.5, while a cellulose acetate propionate (“CAP”) and celluloseacetate butyrate (“CAB”) can have a total DS/AGU of about 1.7 to about2.8.

The cellulose ester can be a cellulose triester or a secondary celluloseester. Examples of cellulose triesters include, but are not limited to,cellulose triacetate, cellulose tripropionate, or cellulose tributyrate.Examples of secondary cellulose esters include cellulose acetate,cellulose acetate propionate, and cellulose acetate butyrate. Thesecellulose esters are described in U.S. Pat. Nos. 1,698,049; 1,683,347;1,880,808; 1,880,560; 1,984,147, 2,129,052; and 3,617,201, which areincorporated herein by reference in their entirety to the extent they donot contradict the statements herein.

In one embodiment of the invention, the cellulose ester is selected fromthe group consisting of cellulose acetate, cellulose acetate propionate,cellulose acetate butyrate, cellulose triacetate, cellulosetripropionate, cellulose tributyrate, and mixtures thereof.

The degree of polymerization (“DP”) as used herein refers to the numberof AGUs per molecule of cellulose ester. In one embodiment of theinvention, the cellulose esters can have a DP of at least about 2, 10,50, or 100. Additionally or alternatively, the cellulose esters can havea DP of not more than about 10,000, 8,000, 6,000, or 5,000.

In certain embodiments, the cellulose esters can have an inherentviscosity (“IV”) of at least about 0.2, 0.4, 0.6, 0.8, or 1.0deciliters/gram as measured at a temperature of 25° C. for a 0.25 gramsample in 100 ml of a 60/40 by weight solution ofphenol/tetrachloroethane. Additionally or alternatively, the celluloseesters can have an IV of not more than about 3.0, 2.5, 2.0, or 1.5deciliters/gram as measured at a temperature of 25° C. for a 0.25 gramsample in 100 ml of a 60/40 by weight solution ofphenol/tetrachloroethane.

In certain embodiments, the cellulose esters can have a falling ballviscosity of at least about 0.005, 0.01, 0.05, 0.1, 0.5, 1, or 5pascals-second (“Pa·s”). Additionally or alternatively, the celluloseesters can have a falling ball viscosity of not more than about 50, 45,40, 35, 30, 25, 20, or 10 Pa·s.

In certain embodiments, the cellulose esters can have a hydroxyl contentof at least about 1.2, 1.4, 1.6, 1.8, or 2.0 weight percent.

In certain embodiments, the cellulose esters useful in the presentinvention can have a weight average molecular weight (M_(w)) of at leastabout 5,000, 10,000, 15,000, or 20,000 as measured by gel permeationchromatography (“GPC”). Additionally or alternatively, the celluloseesters useful in the present invention can have a weight averagemolecular weight (M_(w)) of not more than about 400,000, 300,000,250,000, 100,000, or 80,000 as measured by GPC. In another embodiment,the cellulose esters useful in the present invention can have a numberaverage molecular weight (M_(n)) of at least about 2,000, 4,000, 6,000,or 8,000 as measured by GPC. Additionally or alternatively, thecellulose esters useful in the present invention can have a numberaverage molecular weight (M_(n)) of not more than about 100,000, 80,000,60,000, or 40,000 as measured by GPC.

In certain embodiments, the cellulose esters can have a glass transitiontemperature (“Tg”) of at least about 50° C., 55° C., 60° C., 65° C., 70°C., 75° C., or 80° C. Additionally or alternatively, the celluloseesters can have a Tg of not more than about 200° C., 190° C., 180° C.,170° C., 160° C., 150° C., 140° C., or 130° C.

In one embodiment of the present invention, the cellulose estersutilized in the elastomeric compositions have not previously beensubjected to fibrillation or any other fiber-producing process. In suchan embodiment, the cellulose esters are not in the form of fibrils andcan be referred to as “non-fibril.”

The cellulose esters can be produced by any method known in the art.Examples of processes for producing cellulose esters are taught inKirk-Othmer, Encyclopedia of Chemical Technology, 5th Edition, Vol. 5,Wiley-Interscience, New York (2004), pp. 394-444. Cellulose, thestarting material for producing cellulose esters, can be obtained indifferent grades and from sources such as, for example, cotton linters,softwood pulp, hardwood pulp, corn fiber and other agricultural sources,and bacterial celluloses.

One method of producing cellulose esters is by esterification. In such amethod, the cellulose is mixed with the appropriate organic acids, acidanhydrides, and catalysts and then converted to a cellulose triester.Ester hydrolysis is then performed by adding a water-acid mixture to thecellulose triester, which can be filtered to remove any gel particles orfibers. Water is added to the mixture to precipitate out the celluloseester. The cellulose ester can be washed with water to remove reactionby-products followed by dewatering and drying.

The cellulose triesters that are hydrolyzed can have three substitutentsselected independently from alkanoyls having from 2 to 10 carbon atoms.Examples of cellulose triesters include cellulose triacetate, cellulosetripropionate, and cellulose tributyrate or mixed triesters of cellulosesuch as cellulose acetate propionate and cellulose acetate butyrate.These cellulose triesters can be prepared by a number of methods knownto those skilled in the art. For example, cellulose triesters can beprepared by heterogeneous acylation of cellulose in a mixture ofcarboxylic acid and anhydride in the presence of a catalyst such asH₂SO₄. Cellulose triesters can also be prepared by the homogeneousacylation of cellulose dissolved in an appropriate solvent such asLiCl/DMAc or LiCl/NMP.

Those skilled in the art will understand that the commercial term ofcellulose triesters also encompasses cellulose esters that are notcompletely substituted with acyl groups. For example, cellulosetriacetate commercially available from Eastman Chemical Company, Inc.,Kingsport, Tenn., U.S.A., typically has a DS from about 2.85 to about2.95.

After esterification of the cellulose to the triester, part of the acylsubstitutents can be removed by hydrolysis or by alcoholysis to give asecondary cellulose ester. Secondary cellulose esters can also beprepared directly with no hydrolysis by using a limiting amount ofacylating reagent. This process is particularly useful when the reactionis conducted in a solvent that will dissolve cellulose.

In another embodiment of the invention, low molecular weight mixedcellulose esters can be utilized, such as those disclosed in U.S. Pat.No. 7,585,905, which is incorporated herein by reference to the extentit does not contradict the statements herein.

In one embodiment of the invention, a low molecular weight mixedcellulose ester is utilized that has the following properties: (A) atotal DS/AGU of from about 3.08 to about 3.50 with the followingsubstitutions: a DS/AGU of hydroxyl of not more than about 0.70, aDS/AGU of C3/C4 esters from about 0.80 to about 1.40, and a DS/AGU ofacetyl of from about 1.20 to about 2.34; an IV of from about 0.05 toabout 0.15 dL/g, as measured in a 60/40 (wt./wt.) solution ofphenol/tetrachloroethane at 25° C.; a number average molecular weight offrom about 1,000 to about 5,600; a weight average molecular weight offrom about 1,500 to about 10,000; and a polydispersity of from about 1.2to about 3.5.

In another embodiment of the invention, a low molecular weight mixedcellulose ester is utilized that has the following properties: a totalDS/AGU of from about 3.08 to about 3.50 with the followingsubstitutions: a DS/AGU of hydroxyl of not more than about 0.70; aDS/AGU of C3/C4 esters from about 1.40 to about 2.45, and DS/AGU ofacetyl of from about 0.20 to about 0.80; an IV of from about 0.05 toabout 0.15 dL/g, as measured in a 60/40 (wt./wt.) solution ofphenol/tetrachloroethane at 25° C.; a number average molecular weight offrom about 1,000 to about 5,600; a weight average molecular weight offrom about 1,500 to about 10,000; and a polydispersity of from about 1.2to about 3.5.

In yet another embodiment of the invention, a low molecular weight mixedcellulose ester is utilized that has the following properties: a totalDS/AGU of from about 3.08 to about 3.50 with the followingsubstitutions: a DS/AGU of hydroxyl of not more than about 0.70; aDS/AGU of C3/C4 esters from about 2.11 to about 2.91, and a DS/AGU ofacetyl of from about 0.10 to about 0.50; an IV of from about 0.05 toabout 0.15 dL/g, as measured in a 60/40 (wt./wt.) solution ofphenol/tetrachloroethane at 25° C.; a number average molecular weight offrom about 1,000 to about 5,600; a weight average molecular weight offrom about 1,500 to about 10,000; and a polydispersity of from about 1.2to about 3.5.

In certain embodiments, the cellulose esters utilized in this inventioncan also contain chemical functionality. In such embodiments, thecellulose esters are described herein as “derivatized,” “modified,” or“functionalized” cellulose esters.

Functionalized cellulose esters are produced by reacting the freehydroxyl groups of cellulose esters with a bifunctional reactant thathas one linking group for grafting to the cellulose ester and onefunctional group to provide a new chemical group to the cellulose ester.Examples of such bifunctional reactants include succinic anhydride,which links through an ester bond and provides acid functionality;mercaptosilanes, which links through alkoxysilane bonds and providesmercapto functionality; and isocyanotoethyl methacrylate, which linksthrough a urethane bond and gives methacrylate functionality.

In one embodiment of the invention, the functionalized cellulose esterscomprise at least one functional group selected from the groupconsisting of unsaturation (double bonds), carboxylic acids,acetoacetate, acetoacetate imide, mercapto, melamine, and long alkylchains.

Bifunctional reactants to produce cellulose esters containingunsaturation (double bonds) functionality are described in U.S. Pat.Nos. 4,839,230, 5,741,901, 5,871,573, 5,981,738, 4,147,603, 4,758,645,and 4,861,629; all of which are incorporated by reference to the extentthey do not contradict the statements herein. In one embodiment, thecellulose esters containing unsaturation are produced by reacting acellulose ester containing residual hydroxyl groups with anacrylic-based compound and m-isopropyenyl-α,α′-dimethylbenzylisocyanate. The grafted cellulose ester is a urethane-containing producthaving pendant (meth)acrylate and α-methylstyrene moieties. In anotherembodiment, the cellulose esters containing unsaturation are produced byreacting maleic anhydride and a cellulose ester in the presence of analkaline earth metal or ammonium salt of a lower alkyl monocarboxylicacid catalyst, and at least one saturated monocarboxylic acid have 2 to4 carbon atoms. In another embodiment, the cellulose esters containingunsaturation are produced from the reaction product of (a) at least onecellulosic polymer having isocyanate reactive hydroxyl functionality and(b) at least one hydroxyl reactive poly(α,β ethyleneically unsaturated)isocyanate.

Bifunctional reactants to produce cellulose esters containing carboxylicacid functionality are described in U.S. Pat. Nos. 5,384,163, 5,723,151,and 4,758,645; all of which are incorporated by reference to the extentthey do not contradict the statements herein. In one embodiment, thecellulose esters containing carboxylic acid functionality are producedby reacting a cellulose ester and a mono- or di-ester of maleic orfurmaric acid, thereby obtaining a cellulose derivative having doublebond functionality. In another embodiment, the cellulose esterscontaining carboxylic acid functionality has a first and second residue,wherein the first residue is a residue of a cyclic dicarboxylic acidanhydride and the second residue is a residue of an oleophilicmonocarboxylic acid and/or a residue of a hydrophilic monocarboxylicacid. In yet another embodiment, the cellulose esters containingcarboxylic acid functionality are cellulose acetate phthalates, whichcan be prepared by reacting cellulose acetate with phthalic anhydride.

Bifunctional reactants to produce cellulose esters containingacetoacetate functionality are described in U.S. Pat. No. 5,292,877,which is incorporated by reference to the extent it does not contradictthe statements herein. In one embodiment, the cellulose esterscontaining acetoacetate functionality are produced by contacting: (i)cellulose; (ii) diketene, an alkyl acetoacetate, 2,2,6, trimethyl-4H1,3-dioxin-4-one, or a mixture thereof, and (iii) a solubilizing amountof solvent system comprising lithium chloride plus a carboxamideselected from the group consisting of 1-methyl-2-pyrrolidinone, N,Ndimethylacetamide, or a mixture thereof.

Bifunctional reactants to produce cellulose esters containingacetoacetate imide functionality are described in U.S. Pat. No.6,369,214, which is incorporated by reference to the extent it does notcontradict the statements herein. Cellulose esters containingacetoacetate imide functionality are the reaction product of a celluloseester and at least one acetoacetyl group and an amine functionalcompound comprising at least one primary amine.

Bifunctional reactants to produce cellulose esters containing mercaptofunctionality are described in U.S. Pat. No. 5,082,914, which isincorporated by reference to the extent it does not contradict thestatements herein. In one embodiment of the invention, the celluloseester is grafted with a silicon-containing thiol component which iseither commercially available or can be prepared by procedures known inthe art. Examples of silicon-containing thiol compounds include, but arenot limited to, (3-mercaptopropyl)trimethoxysilane,(3-mercaptopropyl)-dimethyl-methoxysilane,(3-mercaptopropyl)dimethoxymethylsilane,(3-mercaptopropyl)dimethylchlorosilane,(3-mercaptopropyl)dimethylethoxysilane,(3-mercaptopropyl)diethyoxy-methylsilane, and(3-mercapto-propyl)triethoxysilane.

Bifunctional reactants to produce cellulose esters containing melaminefunctionality are described in U.S. Pat. No. 5,182,379, which isincorporated by reference to the extent it does not contradict thestatements herein. In one embodiment, the cellulose esters containingmelamine functionality are prepared by reacting a cellulose ester with amelamine compound to form a grafted cellulose ester having melaminemoieties grafted to the backbone of the anhydrogluclose rings of thecellulose ester. In one embodiment, the melamine compound is selectedfrom the group consisting of methylol ethers of melamine and aminoplastcarrier elastomers.

Bifunctional reactants to produce cellulose esters containing long alkylchain functionality are described in U.S. Pat. No. 5,750,677, which isincorporated by reference to the extent it does not contradict thestatements herein. In one embodiment, the cellulose esters containinglong alkyl chain functionality are produced by reacting cellulose incarboxamide diluents or urea-based diluents with an acylating reagentusing a titanium-containing species. Cellulose esters containing longalkyl chain functionality can be selected from the group consisting ofcellulose acetate hexanoate, cellulose acetate nonanoate, celluloseacetate laurate, cellulose palmitate, cellulose acetate stearate,cellulose nonanoate, cellulose hexanoate, cellulose hexanoatepropionate, and cellulose nonanoate propionate.

In certain embodiments of the invention, the cellulose ester can bemodified using one or more plasticizers. The plasticizer can form atleast about 1, 2, 5, or 10 weight percent of the cellulose estercomposition. Additionally or alternatively, the plasticizer can make upnot more than about 60, 50, 40, or 35 weight percent of the celluloseester composition. In one embodiment, the cellulose ester is a modifiedcellulose ester that was formed by modifying an initial cellulose esterwith a plasticizer.

The plasticizer used for modification can be any that is known in theart that can reduce the melt temperature and/or the melt viscosity ofthe cellulose ester. The plasticizer can be either monomeric orpolymeric in structure. In one embodiment, the plasticizer is at leastone selected from the group consisting of a phosphate plasticizer,benzoate plasticizer, adipate plasticizer, a phthalate plasticizer, aglycolic acid ester, a citric acid ester plasticizer, and ahydroxyl-functional plasticizer.

In one embodiment of the invention, the plasticizer can be selected fromat least one of the following: triphenyl phosphate, tricresyl phosphate,cresyldiphenyl phosphate, octyldiphenyl phosphate, diphenylbiphenylphosphate, trioctyl phosphate, tributyl phosphate, diethyl phthalate,dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutylphthalate, di-2-ethylhexyl phthalate, butylbenzyl phthalate, dibenzylphthalate, butyl phthalyl butyl glycolate, ethyl phthalyl ethylglycolate, methyl phthalyl ethyl glycolate, triethyl citrate,tri-n-butyl citrate, acetyltriethyl citrate, acetyl-tri-n-butyl citrate,and acetyl-tri-n-(2-ethylhexyl) citrate.

In another embodiment of the invention, the plasticizer can be one ormore esters comprising (i) at least one acid residue including residuesof phthalic acid, adipic acid, trimellitic acid, succinic acid, benzoicacid, azelaic acid, terephthalic acid, isophthalic acid, butyric acid,glutaric acid, citric acid, and/or phosphoric acid; and (ii) alcoholresidues comprising one or more residues of an aliphatic,cycloaliphatic, or aromatic alcohol containing up to about 20 carbonatoms.

In another embodiment of the invention, the plasticizer can comprisealcohol residues containing residues selected from the following:stearyl alcohol, lauryl alcohol, phenol, benzyl alcohol, hydroquinone,catechol, resorcinol, ethylene glycol, neopentyl glycol,1,4-cyclohexanedimethanol, and diethylene glycol.

In another embodiment of the invention, the plasticizer can be selectedfrom at least one of the following: benzoates, phthalates, phosphates,arylene-bis(diaryl phosphate), and isophthalates. In another embodiment,the plasticizer comprises diethylene glycol dibenzoate, abbreviatedherein as “DEGDB”.

In another embodiment of the invention, the plasticizer can comprisealiphatic polyesters containing C2-10 diacid residues such as, forexample, malonic acid, succinic acid, glutaric acid, adipic acid,pimelic acid, suberic acid, azelaic acid, and sebacic acid; and C2-10diol residues.

In another embodiment, the plasticizer can comprise diol residues whichcan be residues of at least one of the following C2-C10 diols: ethyleneglycol, diethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol,1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, neopentylglycol, 1,5-pentanediol, 1,6 hexanediol, 1,5-pentylene glycol,triethylene glycol, and tetraethylene glycol.

In another embodiment of the invention, the plasticizer can includepolyglycols, such as, for example, polyethylene glycol, polypropyleneglycol, and polybutylene glycol. These can range from low molecularweight dimers and trimers to high molecular weight oligomers andpolymers. In one embodiment, the molecular weight of the polyglycol canrange from about 200 to about 2,000.

In another embodiment of the invention, the plasticizer comprises atleast one of the following: Resoflex® R296 plasticizer, Resoflex® 804plasticizer, SHP (sorbitol hexapropionate), XPP (xylitolpentapropionate), XPA (xylitol pentaacetate), GPP (glucosepentaacetate), GPA (glucose pentapropionate), and APP (arabitolpentapropionate).

In another embodiment of the invention, the plasticizer comprises one ormore of: A) from about 5 to about 95 weight percent of a C2-C12carbohydrate organic ester, wherein the carbohydrate comprises fromabout 1 to about 3 monosaccharide units; and B) from about 5 to about 95weight percent of a C2-C12 polyol ester, wherein the polyol is derivedfrom a C5 or C6 carbohydrate. In one embodiment, the polyol ester doesnot comprise or contain a polyol acetate or polyol acetates.

In another embodiment, the plasticizer comprises at least onecarbohydrate ester and the carbohydrate portion of the carbohydrateester is derived from one or more compounds selected from the groupconsisting of glucose, galactose, mannose, xylose, arabinose, lactose,fructose, sorbose, sucrose, cellobiose, cellotriose, and raffinose.

In another embodiment of the invention, the plasticizer comprises atleast one carbohydrate ester and the carbohydrate portion of thecarbohydrate ester comprises one or more of α-glucose pentaacetate,β-glucose pentaacetate, α-glucose pentapropionate, β-glucosepentapropionate, α-glucose pentabutyrate, and β-glucose pentabutyrate.

In another embodiment, the plasticizer comprises at least onecarbohydrate ester and the carbohydrate portion of the carbohydrateester comprises an α-anomer, a β-anomer, or a mixture thereof.

In another embodiment of the invention, the plasticizer can be a solid,non-crystalline carrier elastomer. These carrier elastomers can containsome amount of aromatic or polar functionality and can lower the meltviscosity of the cellulose esters. In one embodiment of the invention,the plasticizer can be a solid, non-crystalline compound, such as, forexample, a rosin; a hydrogenated rosin; a stabilized rosin, and theirmonofunctional alcohol esters or polyol esters; a modified rosinincluding, but not limited to, maleic- and phenol-modified rosins andtheir esters; terpene elastomers; phenol-modified terpene elastomers;coumarin-indene elastomers; phenolic elastomers; alkylphenol-acetyleneelastomers; and phenol-formaldehyde elastomers.

In another embodiment of the invention, the plasticizer can be atackifier resin. Any tackifier known to a person of ordinary skill inthe art may be used in the elastomeric compositions. Tackifiers suitablefor the compositions disclosed herein can be solids, semi-solids, orliquids at room temperature. Non-limiting examples of tackifiers include(1) natural and modified rosins (e.g., gum rosin, wood rosin, tall oilrosin, distilled rosin, hydrogenated rosin, dimerized rosin, andpolymerized rosin); (2) glycerol and pentaerythritol esters of naturaland modified rosins (e.g., the glycerol ester of pale, wood rosin, theglycerol ester of hydrogenated rosin, the glycerol ester of polymerizedrosin, the pentaerythritol ester of hydrogenated rosin, and thephenolic-modified pentaerythritol ester of rosin); (3) copolymers andterpolymers of natured terpenes (e.g., styrene/terpene and alpha methylstyrene/terpene); (4) polyterpene resins and hydrogenated polyterpeneresins; (5) phenolic modified terpene resins and hydrogenatedderivatives thereof (e.g., the resin product resulting from thecondensation, in an acidic medium, of a bicyclic terpene and a phenol);(6) aliphatic or cycloaliphatic hydrocarbon resins and the hydrogenatedderivatives thereof (e.g., resins resulting from the polymerization ofmonomers consisting primarily of olefins and diolefins); (7) aromatichydrocarbon resins and the hydrogenated derivatives thereof; and (8)aromatic modified aliphatic or cycloaliphatic hydrocarbon resins and thehydrogenated derivatives thereof; and combinations thereof.

In another embodiment of the invention, the tackifier resins includerosin-based tackifiers (e.g. AQUATAC® 9027, AQUATAC® 4188, SYLVALITE®,SYLVATAC® and SYL V AGUM® rosin esters from Arizona Chemical,Jacksonville, Fla.). In other embodiments, the tackifiers includepolyterpenes or terpene resins (e.g., SYLVARES® 15 terpene resins fromArizona Chemical, Jacksonville, Fla.). In other embodiments, thetackifiers include aliphatic hydrocarbon resins such as resins resultingfrom the polymerization of monomers consisting of olefins and diolefins(e.g., ESCOREZ® 1310LC, ESCOREZ® 2596 from ExxonMobil Chemical Company,Houston, Tex. or PICCOTAC® 1095 from Eastman Chemical Company,Kingsport, Tenn.) and the hydrogenated derivatives 20 thereof; alicyclicpetroleum hydrocarbon resins and the hydrogenated derivatives thereof(e.g. ESCOREZ® 5300 and 5400 series from ExxonMobil Chemical Company;EASTOTAC® resins from Eastman Chemical Company). In some embodiments,the tackifiers include hydrogenated cyclic hydrocarbon resins (e.g.REGALREZ® and REGALITE® resins from Eastman Chemical Company). Infurther embodiments, the tackifiers are modified with tackifiermodifiers including aromatic compounds (e.g., ESCOREZ® 2596 fromExxonMobil Chemical Company or PICCOTAC® 7590 from Eastman ChemicalCompany) and low softening point resins (e.g., AQUATAC 5527 from ArizonaChemical, Jacksonville, Fla.). In some embodiments, the tackifier is analiphatic hydrocarbon resin having at least five carbon atoms.

In certain embodiments of the present invention, the cellulose ester canbe modified using one or more compatibilizers. The compatibilizer cancomprise at least about 1, 2, 3, or 5 weight percent of the celluloseester composition. Additionally or alternatively, the compatibilizer cancomprise not more than about 40, 30, 25, or 20 weight percent of thecellulose ester composition.

The compatibilizer can be either a non-reactive compatibilizer or areactive compatibilizer. The compatibilizer can enhance the ability ofthe cellulose ester to reach a desired small particle size therebyimproving the dispersion of the cellulose ester into an elastomer. Thecompatibilizers used can also improve mechanical and physical propertiesof the elastomeric compositions by enhancing the interfacialinteraction/bonding between the cellulose ester and the elastomer.

When non-reactive compatibilizers are utilized, the compatibilizer cancontain a first segment that is compatible with the cellulose ester anda second segment that is compatible with the elastomer. In this case,the first segment contains polar functional groups, which providecompatibility with the cellulose ester, including, but not limited to,such polar functional groups as ethers, esters, amides, alcohols,amines, ketones, and acetals. The first segment may include oligomers orpolymers of the following: cellulose esters; cellulose ethers;polyoxyalkylene, such as, polyoxyethylene, polyoxypropylene, andpolyoxybutylene; polyglycols, such as, polyethylene glycol,polypropylene glycol, and polybutylene glycol; polyesters, such as,polycaprolactone, polylactic acid, aliphatic polyesters, andaliphatic-aromatic copolyesters; polyacrylates and polymethacrylates;polyacetals; polyvinylpyrrolidone; polyvinyl acetate; and polyvinylalcohol. In one embodiment, the first segment is polyoxyethylene orpolyvinyl alcohol.

The second segment can be compatible with the elastomer and containnonpolar groups. The second segment can contain saturated and/orunsaturated hydrocarbon groups. In one embodiment, the second segmentcan be an oligomer or a polymer. In another embodiment, the secondsegment of the non-reactive compatibilizer is selected from the groupconsisting of polyolefins, polydienes, polyaromatics, and copolymers.

In one embodiment, the first and second segments of the non-reactivecompatibilizers can be in a diblock, triblock, branched, or combstructure. In this embodiment, the molecular weight of the non-reactivecompatibilizers can range from about 300 to about 20,000, 500 to about10,000, or 1,000 to about 5,000. The segment ratio of the non-reactivecompatibilizers can range from about 15 to about 85 percent polar firstsegments to about 15 to about 85 percent nonpolar second segments.

Examples of non-reactive compatibilizers include, but are not limitedto, ethoxylated alcohols, ethoxylated alkylphenols, ethoxylated fattyacids, block polymers of propylene oxide and ethylene oxide,polyglycerol esters, polysaccharide esters, and sorbitan esters.Examples of ethoxylated alcohols are C11-C15 secondary alcoholethoxylates, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether,and C12-C14 natural liner alcohol ethoxylated with ethylene oxide.C11-C15 secondary ethyoxylates can be obtained as Dow Tergitol® 15S fromthe Dow Chemical Company. Polyoxyethlene cetyl ether and polyoxyethylenestearyl ether can be obtained from ICI Surfactants under the Brij®series of products. C12-C14 natural linear alcohol ethoxylated withethylene oxide can be obtained from Hoechst Celanese under the Genapol®series of products. Examples of ethoxylated alkylphenols includeoctylphenoxy poly(ethyleneoxy)ethanol and nonylphenoxypoly(ethyleneoxy)ethanol. Octylphenoxy poly(ethyleneoxy)ethanol can beobtained as Igepal® CA series of products from Rhodia, and nonylphenoxypoly(ethyleneoxy)ethanol can be obtained as Igepal CO series of productsfrom Rhodia or as Tergitol® NP from Dow Chemical Company. Ethyoxylatedfatty acids include polyethyleneglycol monostearate or monolaruate whichcan be obtained from Henkel under the Nopalcol® series of products.Block polymers of propylene oxide and ethylene oxide can be obtainedunder the Pluronic® series of products from BASF. Polyglycerol esterscan be obtained from Stepan under the Drewpol® series of products.Polysaccharide esters can be obtained from Henkel under the Glucopon®series of products, which are alkyl polyglucosides. Sorbitan esters canbe obtained from ICI under the Tween® series of products.

In another embodiment of the invention, the non-reactive compatibilizerscan be synthesized in situ in the cellulose ester composition or thecellulose ester/primary elastomer composition by reacting celluloseester-compatible compounds with elastomer-compatible compounds. Thesecompounds can be, for example, telechelic oligomers, which are definedas prepolymers capable of entering into further polymerization or otherreaction through their reactive end groups. In one embodiment of theinvention, these in situ compatibilizers can have higher molecularweight from about 10,000 to about 1,000,000.

In another embodiment of the invention, the compatibilizer can bereactive. The reactive compatibilizer comprises a polymer or oligomercompatible with one component of the composition and functionalitycapable of reacting with another component of the composition. There aretwo types of reactive compatibilizers. The first reactive compatibilizerhas a hydrocarbon chain that is compatible with a nonpolar elastomer andalso has functionality capable of reacting with the cellulose ester.Such functional groups include, but are not limited to, carboxylicacids, anhydrides, acid chlorides, epoxides, and isocyanates. Specificexamples of this type of reactive compatibilizer include, but are notlimited to: long chain fatty acids, such as stearic acid (octadecanoicacid); long chain fatty acid chlorides, such as stearoyl chloride(octadecanoyl chloride); long chain fatty acid anhydrides, such asstearic anhydride (octadecanoic anhydride); epoxidized oils and fattyesters; styrene maleic anhydride copolymers; maleic anhydride graftedpolypropylene; copolymers of maleic anhydride with olefins and/oracrylic esters, such as terpolymers of ethylene, acrylic ester andmaleic anhydride; and copolymers of glycidyl methacrylate with olefinsand/or acrylic esters, such as terpolymers of ethylene, acrylic ester,and glycidyl methacrylate.

Reactive compatibilizers can be obtained as SMA® 3000 styrene maleicanhydride copolymer from Sartomer/Cray Valley, Eastman G-3015® maleicanhydride grafted polypropylene from Eastman Chemical Company, Epolene®E-43 maleic anhydride grafted polypropylene obtained from WestlakeChemical, Lotader® MAH 8200 random terpolymer of ethylene, acrylicester, and maleic anhydride obtained from Arkema, Lotader® GMA AX 8900random terpolymer of ethylene, acrylic ester, and glycidyl methacrylate,and Lotarder® GMA AX 8840 random terpolymer of ethylene, acrylic ester,and glycidyl methacrylate.

The second type of reactive compatibilizer has a polar chain that iscompatible with the cellulose ester and also has functionality capableof reacting with a nonpolar elastomer. Examples of these types ofreactive compatibilizers include cellulose esters or polyethyleneglycols with olefin or thiol functionality. Reactive polyethylene glycolcompatibilizers with olefin functionality include, but are not limitedto, polyethylene glycol allyl ether and polyethylene glycol acrylate. Anexample of a reactive polyethylene glycol compatibilizer with thiolfunctionality includes polyethylene glycol thiol. An example of areactive cellulose ester compatibilizer includes mercaptoacetatecellulose ester.

(B) Primary Elastomers

The elastomeric composition of the present invention comprises at leastone primary elastomer. The term “elastomer,” as used herein, can be usedinterchangeably with the term “rubber.” Due to the wide applicability ofthe process described herein, the cellulose esters can be employed withvirtually any type of primary elastomer. For instance, the primaryelastomers utilized in this invention can comprise a natural rubber, amodified natural rubber, a synthetic rubber, and mixtures thereof.

In certain embodiments of the present invention, at least one of theprimary elastomers is a non-polar elastomer. For example, a non-polarprimary elastomer can comprise at least about 90, 95, 98, 99, or 99.9weight percent of non-polar monomers. In one embodiment, the non-polarprimary elastomer is primarily based on a hydrocarbon. Examples ofnon-polar primary elastomers include, but are not limited to, naturalrubber, polybutadiene rubber, polyisoprene rubber, styrene-butadienerubber, polyolefins, ethylene propylene diene monomer (EPDM) rubber, andpolynorbornene rubber. Examples of polyolefins include, but are notlimited to, polybutylene, polyisobutylene, and ethylene propylenerubber. In another embodiment, the primary elastomer comprises a naturalrubber, a styrene-butadiene rubber, and/or a polybutadiene rubber.

In certain embodiments, the primary elastomer contains little or nonitrile groups. As used herein, the primary elastomer is considered a“non-nitrile” primary elastomer when nitrile monomers make up less than10 weight percent of the primary elastomer. In one embodiment, theprimary elastomer contains no nitrile groups.

(C) Fillers

In certain embodiments, the elastomeric composition of the presentinvention can comprise one or more fillers.

The fillers can comprise any filler that can improve the thermophysicalproperties of the elastomeric composition (e.g., modulus, strength, andexpansion coefficient). For example, the fillers can comprise silica,carbon black, clay, alumina, talc, mica, discontinuous fibers includingcellulose fibers and glass fibers, aluminum silicate, aluminumtrihydrate, barites, feldspar, nepheline, antimony oxide, calciumcarbonate, kaolin, and combinations thereof. In one embodiment, thefillers comprise an inorganic and nonpolymeric material. In anotherembodiment, the fillers comprise silica and/or carbon black. In yetanother embodiment, the fillers comprise silica.

In certain embodiments, the elastomeric composition can comprise atleast about 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50 phr of one or morefillers, based on the total weight of the elastomers. Additionally oralternatively, the elastomeric composition can comprise not more thanabout 150, 140, 130, 120, 110, 100, 90, 80, 70, or 60 phr of one or morefillers, based on the total weight of the elastomers.

In certain embodiments, the elastomeric composition is a highly-filledelastomeric composition. As used herein, a “highly-filled” elastomericcomposition comprises at least about 60 phr of one or more fillers,based on the total weight of the elastomers. In one embodiment, ahighly-filled elastomeric composition comprises at least about 65, 70,75, 80, 85, 90, or 95 phr of one or more fillers, based on the totalweight of the elastomers. Additionally or alternatively, thehighly-filled elastomeric composition can comprise not more than about150, 140, 130, 120, 110, or 100 phr of one or more fillers, based on thetotal weight of the elastomers.

In certain embodiments, the elastomeric composition is not highly-filledand contains minor amounts of filler. In such an embodiment, theelastomeric composition can comprise at least about 5, 10, or 15 phrand/or not more than about 60, 50, or 40 phr of one or more fillers,based on the total weight of the elastomers.

(D) Optional Additives

The elastomeric composition of the present invention can comprise one ormore additives.

In certain embodiments, the elastomeric composition can comprise atleast about 1, 2, 5, 10, or 15 phr of one or more additives, based onthe total weight of the elastomers. Additionally or alternatively, theelastomeric composition can comprise not more than about 70, 50, 40, 30,or phr of one or more additives, based on the total weight of theelastomers.

The additives can comprise, for example, processing aids, carrierelastomers, tackifiers, lubricants, oils, waxes, surfactants,stabilizers, UV absorbers/inhibitors, pigments, antioxidants, extenders,reactive coupling agents, and/or branchers. In one embodiment, theadditives comprise one or more cellulose ethers, starches, and/orderivatives thereof. In such an embodiment, the cellulose ethers,starches and/or derivatives thereof can include, for example, amylose,acetoxypropyl cellulose, amylose triacetate, amylose tributyrate,amylose tricabanilate, amylose tripropionate, carboxymethyl amylose,ethyl cellulose, ethyl hydroxyethyl cellulose, hydroxyethyl cellulose,methyl cellulose, sodium carboxymethyl cellulose, and sodium cellulosexanthanate.

In one embodiment, the additives comprise a non-cellulose esterprocessing aid. The non-cellulose ester processing aid can comprise, forexample, a processing oil, starch, starch derivatives, and/or water. Insuch an embodiment, the elastomeric composition can comprise less thanabout 10, 5, 3, or 1 phr of the non-cellulose ester processing aid,based on the total weight of the elastomers. Additionally oralternatively, the elastomeric composition can exhibit a weight ratio ofcellulose ester to non-cellulose ester processing aid of at least about0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 8:1, or 10:1.

In another embodiment, the elastomeric composition can comprise a starchand/or its derivatives. In such an embodiment, the elastomericcomposition can comprise less than 10, 5, 3, or 1 phr of starch and itsderivatives, based on the total weight of the elastomers. Additionallyor alternatively, the elastomeric composition can exhibit a weight ratioof cellulose ester to starch of at least about 3:1, 4:1, 5:1, 8:1, or10:1.

(E) Processes for Producing Elastomeric Compositions

The elastomeric compositions of the present invention can be produced bytwo different types of processes. The first process involves directlymelt dispersing the cellulose ester into a primary elastomer. The secondprocess involves mixing a cellulose ester with a carrier elastomer toproduce a cellulose ester concentrate, and then blending the celluloseester concentrate with a primary elastomer.

In the first process, a cellulose ester is blended directly with aprimary elastomer to produce an elastomeric composition. In certainembodiments, the first process comprises: a) blending at least oneprimary elastomer, at least one cellulose ester, and, optionally, one ormore fillers for a sufficient time and temperature to disperse thecellulose ester throughout the primary elastomer so as to produce theelastomeric composition. A sufficient temperature for blending thecellulose ester and the primary elastomer can be the flow temperature ofthe cellulose ester, which is higher than the Tg of the cellulose esterby at least about 10° C., 15° C., 20° C., 25° C., 30° C., 35° C., 40°C., 45° C., or 50° C. The temperature of the blending can be limited bythe primary elastomer's upper processing temperature range and the lowerprocessing temperature range of the cellulose ester.

The primary elastomer, cellulose ester, fillers, and additives can beadded or combined in any order during the process. In one embodiment,the cellulose ester can be modified with a plasticizer and/orcompatibilizer prior to being blended with the primary elastomer.

In certain embodiments of the first process, at least a portion of theblending can occur at temperatures of at least about 80° C., 100° C.,120° C., 130° C., or 140° C. Additionally or alternatively, at least aportion of the blending can occur at temperatures of not more than about220° C., 200° C., 190° C., 170° C., or 160° C.

During this first process, the cellulose esters can effectively softenand/or melt, thus allowing the cellulose esters to form intosufficiently small particle sizes under the specified blendingconditions. In such an embodiment, due to the small particle sizes, thecellulose esters can be thoroughly dispersed throughout the primaryelastomer during the process. In one embodiment, the particles of thecellulose ester in the elastomeric composition have a spherical ornear-spherical shape. As used herein, a “near-spherical” shape isunderstood to include particles having a cross-sectional aspect ratio ofless than 2:1. In more particular embodiments, the spherical andnear-spherical particles have a cross-sectional aspect ratio of lessthan 1.5:1, 1.2:1, or 1.1:1. The “cross-sectional aspect ratio” as usedherein is the ratio of the longest dimension of the particle'scross-section relative to its shortest dimension. In a furtherembodiment, at least about 75, 80, 85, 90, 95, or 99.9 percent of theparticles of cellulose esters in the elastomeric composition have across-sectional aspect ratio of not more than about 10:1, 8:1, 6:1, or4:1.

In certain embodiments, at least about 75, 80, 85, 90, 95, or 99.9percent of the cellulose ester particles have a diameter of not morethan about 10, 8, 5, 4, 3, 2, or 1 μm subsequent to blending thecellulose ester with the primary elastomer.

In certain embodiments, the cellulose esters added at the beginning ofthe process are in the form of a powder having particle sizes rangingfrom 200 to 400 μm. In such an embodiment, subsequent to blending thecellulose ester into the primary elastomer, the particle sizes of thecellulose ester can decrease by at least about 50, 75, 90, 95, or 99percent relative to their particle size prior to blending.

In certain embodiments, the fillers can have a particle size that isconsiderably smaller than the size of the cellulose ester particles. Forinstance, the fillers can have an average particle size that is not morethan about 50, 40, 30, 20, or 10 percent of the average particle size ofthe cellulose ester particles in the elastomeric composition.

In the second process, a cellulose ester is first mixed with a carrierelastomer to produce a cellulose ester concentrate (i.e., a celluloseester masterbatch), which can subsequently be blended with a primaryelastomer to produce the elastomeric composition. This second processmay also be referred to as the “masterbatch process.” One advantage ofthis masterbatch process is that it can more readily disperse celluloseesters having a higher Tg throughout the primary elastomer. In oneembodiment, the masterbatch process involves mixing a high Tg celluloseester with a compatible carrier elastomer to produce a cellulose esterconcentrate, and then blending the cellulose ester concentrate with atleast one primary elastomer to produce the elastomeric composition.

In certain embodiments, the masterbatch process comprises the followingsteps: a) mixing at least one cellulose ester with at least one carrierelastomer for a sufficient time and temperature to mix the celluloseester and the carrier elastomer to thereby produce a cellulose esterconcentrate; and b) blending the cellulose ester concentrate and atleast one primary elastomer to produce the elastomeric composition. Asufficient temperature for mixing the cellulose ester and the carrierelastomer can be the flow temperature of the cellulose ester, which ishigher than the Tg of the cellulose ester by at least about 10° C., 15°C., 20° C., 25° C., 30° C., 35° C., 40° C., 45° C., or 50° C. In oneembodiment of the masterbatch process, the cellulose ester has a Tg ofat least about 90° C., 95° C., 100° C., 105° C., or 110° C. Additionallyor alternatively, the cellulose ester can have a Tg of not more thanabout 200° C., 180° C., 170° C., 160° C., or 150° C. In a furtherembodiment, at least a portion of the mixing of step (a) occurs at atemperature that is at least 10° C., 15° C., 20° C., 30° C., 40° C., or50° C. greater than the temperature of the blending of step (b).

In certain embodiments, at least a portion of the mixing of thecellulose ester and the carrier elastomer occurs at a temperature of atleast about 170° C., 180° C., 190° C., 200° C., or 210° C. Additionallyor alternatively, at least a portion of the mixing of the celluloseester and the carrier elastomer occurs at a temperature below 260° C.,250° C., 240° C., 230° C., or 220° C.

In certain embodiments, at least a portion of the blending of thecellulose ester concentrate and the primary elastomer occurs at atemperature that will not degrade the primary elastomer. For instance,at least a portion of the blending can occur at a temperature of notmore than about 180° C., 170° C., 160° C., or 150° C.

Fillers and/or additives can be added during any step of the masterbatchprocess. In one embodiment, the cellulose ester can be modified with aplasticizer or compatibilizer prior to the masterbatch process.

In certain embodiments, at least a portion of the cellulose esterconcentrate can be subjected to fibrillation prior to being blended withthe primary elastomer. In such embodiments, the resulting fibrils of thecellulose ester concentrate can have an aspect ratio of at least about2:1, 4:1, 6:1, or 8:1. In an alternative embodiment, at least a portionof the cellulose ester concentrate can be pelletized or granulated priorto being blended with the primary elastomer.

In certain embodiments, the cellulose ester concentrate can comprise atleast about 10, 15, 20, 25, 30, 35, or 40 weight percent of at least onecellulose ester. Additionally or alternatively, the cellulose esterconcentrate can comprise not more than about 90, 85, 80, 75, 70, 65, 60,55, or 50 weight percent of at least one cellulose ester. In oneembodiment, the cellulose ester concentrate can comprise at least about10, 15, 20, 25, 30, 35, or 40 weight percent of at least one carrierelastomer. Additionally or alternatively, the cellulose esterconcentrate can comprise not more than about 90, 85, 80, 75, 70, 65, 60,55, or 50 weight percent of at least one carrier elastomer.

Similar to the first process, the cellulose esters can effectivelysoften and/or melt during the masterbatch process, thus allowing thecellulose esters to form into sufficiently small particle sizes underthe specified blending conditions. In such an embodiment, due to thesmall particle sizes, the cellulose esters can be thoroughly dispersedthroughout the elastomeric composition after the process. In oneembodiment, the particles of cellulose ester in the elastomericcomposition have a spherical or near-spherical shape. In one embodiment,subsequent to blending the cellulose ester concentrate with the primaryelastomer, the cellulose esters are in the form of spherical andnear-spherical particles having a cross-sectional aspect ratio of lessthan 2:1, 1.5:1, 1.2:1, or 1.1:1. In a further embodiment, subsequent toblending the cellulose ester concentrate with the primary elastomer, atleast about 75, 80, 85, 90, 95, or 99.9 percent of the particles ofcellulose esters have a cross-sectional aspect ratio of not more thanabout 2:1, 1.5:1, 1.2:1, or 1.1:1.

In certain embodiments, at least about 75, 80, 85, 90, 95, or 99.9percent of the cellulose ester particles have a diameter of not morethan about 10, 8, 5, 4, 3, 2, or 1 μm subsequent to blending thecellulose ester concentrate with the primary elastomer.

In certain embodiments, the cellulose esters added at the beginning ofthe masterbatch process are in the form of a powder having particlesizes ranging from 200 to 400 μm. In such an embodiment, subsequent toblending the cellulose ester concentrate with the primary elastomer, theparticle sizes of the cellulose ester can decrease by at least about 90,95, 98, 99, or 99.5 percent relative to their particle size prior to themasterbatch process.

The carrier elastomer can be virtually any uncured elastomer that iscompatible with the primary elastomer and that can be processed at atemperature exceeding 160° C. The carrier elastomer can comprise, forexample, styrene block copolymers, polybutadienes, natural rubbers,synthetic rubbers, acrylics, maleic anhydride modified styrenics,recycled rubber, crumb rubber, powdered rubber, isoprene rubber, nitrilerubber, and combinations thereof. The styrene block copolymers caninclude, for example, styrene-butadiene block copolymers and styreneethylene-butylene block copolymers having a styrene content of at leastabout 5, 10, or 15 weight percent and/or not more than about 40, 35, or30 weight percent. In one embodiment, the carrier elastomers have a Tgthat is less than the Tg of the cellulose ester.

In certain embodiments, the carrier elastomer comprises styrene blockcopolymers, polybutadienes, natural rubbers, synthetic rubbers,acrylics, maleic anhydride modified styrenics, and combinations thereof.In one embodiment, the carrier elastomer comprises 1,2 polybutadiene. Inanother embodiment, the carrier elastomer comprises a styrene blockcopolymer. In yet another embodiment, the carrier elastomer comprises amaleic anhydride-modified styrene ethylene-butylene elastomer.

In certain embodiments, the melt viscosity ratio of the cellulose esterto the carrier elastomer is at least about 0.1, 0.2, 0.3, 0.5, 0.8, or1.0 as measured at 170° C. and a shear rate of 400 s⁻¹. Additionally oralternatively, the melt viscosity ratio of the cellulose ester to thecarrier elastomer is not more than about 2, 1.8, 1.6, 1.4, or 1.2 asmeasured at 170° C. and a shear rate of 400 s⁻¹.

In certain embodiments, the melt viscosity ratio of the cellulose esterconcentrate to the primary elastomer is at least about 0.1, 0.2, 0.3,0.5, 0.8, or 1.0 as measured at 160° C. and a shear rate of 200 s⁻¹.Additionally or alternatively, the melt viscosity ratio of the celluloseester concentrate to the primary elastomer is not more than about 2,1.8, 1.6, 1.4, or 1.2 as measured at as measured at 160° C. and a shearrate of 200 s⁻¹.

In certain embodiments, the cellulose ester exhibits a melt viscosity ofat least about 75,000, 100,000, or 125,000 poise as measured at 170° C.and a shear rate of 1 rad/sec. Additionally or alternatively, thecellulose ester can exhibit a melt viscosity of not more than about1,000,000, 900,000, or 800,000 poise as measured at 170° C. and a shearrate of 1 rad/sec. In another embodiment, the carrier elastomer exhibitsa melt viscosity of at least about 75,000, 100,000, or 125,000 poise asmeasured at 170° C. and a shear rate of 1 rad/sec. Additionally oralternatively, the carrier elastomer can exhibit a melt viscosity of notmore than about 2,000,000, 1,750,000, or 1,600,000 poise as measured at170° C. and a shear rate of 1 rad/sec.

In certain embodiments, the cellulose ester exhibits a melt viscosity ofat least about 25,000, 40,000, or 65,000 poise as measured at 170° C.and a shear rate of 10 rad/sec. Additionally or alternatively, thecellulose ester can exhibit a melt viscosity of not more than about400,000, 300,000, or 200,000 poise as measured at 170° C. and a shearrate of 10 rad/sec. In another embodiment, the carrier elastomerexhibits a melt viscosity of at least about 20,000, 30,000, or 40,000poise as measured at 170° C. and a shear rate of 10 rad/sec.Additionally or alternatively, the carrier elastomer can exhibit a meltviscosity of not more than about 500,000, 400,000, or 300,000 poise asmeasured at 170° C. and a shear rate of 10 rad/sec.

In certain embodiments, the cellulose ester exhibits a melt viscosity ofat least about 10,000, 15,000, or 20,000 poise as measured at 170° C.and a shear rate of 100 rad/sec. Additionally or alternatively, thecellulose ester can exhibit a melt viscosity of not more than about100,000, 75,000, or 50,000 poise as measured at 170° C. and a shear rateof 100 rad/sec. In another embodiment, the carrier elastomer exhibits amelt viscosity of at least about 10,000, 15,000, or 20,000 poise asmeasured at 170° C. and a shear rate of 100 rad/sec. Additionally oralternatively, the carrier elastomer can exhibit a melt viscosity of notmore than about 100,000, 75,000, or 50,000 poise as measured at 170° C.and a shear rate of 100 rad/sec.

In certain embodiments, the cellulose ester exhibits a melt viscosity ofat least about 2,000, 5,000, or 8,000 poise as measured at 170° C. and ashear rate of 400 rad/sec. Additionally or alternatively, the celluloseester can exhibit a melt viscosity of not more than about 30,000,25,000, or 20,000 poise as measured at 170° C. and a shear rate of 400rad/sec. In another embodiment, the carrier elastomer exhibits a meltviscosity of at least about 1,000, 4,000, or 7,000 poise as measured at170° C. and a shear rate of 400 rad/sec. Additionally or alternatively,the carrier elastomer can exhibit a melt viscosity of not more thanabout 30,000, 25,000, or 20,000 poise as measured at 170° C. and a shearrate of 400 rad/sec.

In certain embodiments, the carrier elastomer contains little or nonitrile groups. As used herein, the carrier elastomer is considered a“non-nitrile” carrier elastomer when nitrile monomers make up less than10 weight percent of the carrier elastomer. In one embodiment, thecarrier elastomer contains no nitrile groups.

In one embodiment, the carrier elastomer is the same as the primaryelastomer. In another embodiment, the carrier elastomer is differentfrom the primary elastomer.

The elastomeric compositions produced using either of the aboveprocesses can be subjected to curing to thereby produce a curedelastomeric composition. The curing can be accomplished using anyconventional method, such as curing under conditions of elevatedtemperature and pressure for a suitable period of time. For example, thecuring process can involve subjecting the elastomeric composition to atemperature of at least 160° C. over a period of at least 15 minutes.Examples of curing systems that can be used include, but are not limitedto, sulfur-based systems, resin-curing systems, soap/sulfur curingsystems, urethane crosslinking agents, bisphenol curing agents, silanecrosslinking, isocyanates, poly-functional amines, high-energyradiation, metal oxide crosslinking, and/or peroxide cross-linking.

The mixing and blending of the aforementioned processes can beaccomplished by any method known in the art that is sufficient to mixcellulose esters and elastomers. Examples of mixing equipment include,but are not limited to, Banbury mixers, Brabender mixers, roll mills,planetary mixers, single screw extruders, and twin screw extruders. Theshear energy during the mixing is dependent on the combination ofequipment, blade design, rotation speed (rpm), and mixing time. Theshear energy should be sufficient for breaking down softened/meltedcellulose ester to a small enough size to disperse the cellulose esterthroughout the primary elastomer. For example, when a Banbury mixer isutilized, the shear energy and time of mixing can range from about 5 toabout 15 minutes at 100 rpms. In certain embodiments of the presentinvention, at least a portion of the blending and/or mixing stagesdiscussed above can be carried out at a shear rate of at least about 50,75, 100, 125, or 150 s⁻¹. Additionally or alternatively, at least aportion of the blending and/or mixing stages discussed above can becarried out at a shear rate of not more than about 1,000, 900, 800, 600,or 550 s⁻¹.

It is known in the art that the efficiency of mixing two or moreviscoelastic materials can depend on the ratio of the viscosities of theviscoelastic materials. For a given mixing equipment and shear raterange, the viscosity ratio of the dispersed phase (cellulose ester,fillers, and additives) and continuous phase (primary elastomer) shouldbe within specified limits for obtaining adequate particle size. In oneembodiment of the invention where low shear rotational shearingequipment is utilized, such as, Banbury and Brabender mixers, theviscosity ratio of the dispersed phase (e.g., cellulose ester, fillers,and additives) to the continuous phase (e.g., primary elastomer) canrange from about 0.001 to about 5, from about 0.01 to about 5, and fromabout 0.1 to about 3. In yet another embodiment of the invention wherehigh shear rotational/extensional shearing equipment is utilized, suchas, twin screw extruders, the viscosity ratio of the dispersed phase(e.g., cellulose ester, fillers, and additives) to the continuous phase(e.g., primary elastomer) can range from about 0.001 to about 500 andfrom about 0.01 to about 100.

It is also known in the art that when mixing two or more viscoelasticmaterials, the difference between the interfacial energy of the twoviscoelastic materials can affect the efficiency of mixing. Mixing canbe more efficient when the difference in the interfacial energy betweenthe materials is minimal. In one embodiment of the invention, thesurface tension difference between the dispersed phase (e.g., celluloseester, fillers, and additives) and continuous phase (e.g., primaryelastomer) is less than about 100 dynes/cm, less than 50 dynes/cm, orless than 20 dynes/cm.

(F) Elastomeric Compositions

The elastomeric compositions of the present invention can exhibit anumber of improvements associated with processability, strength,modulus, and elasticity.

In certain embodiments, the uncured elastomeric composition exhibits aMooney Viscosity as measured at 100° C. and according to ASTM D 1646 ofnot more than about 110, 105, 100, 95, 90, or 85 AU. A lower MooneyViscosity makes the uncured elastomeric composition easier to process.In another embodiment, the uncured elastomeric composition exhibits aPhillips Dispersion Rating of at least 6.

In certain embodiments, the uncured elastomeric composition exhibits ascorch time of at least about 1.8, 1.9, 2.0, 2.1, or 2.2 Ts2, min. Alonger scorch time enhances processability in that it provides a longertime to handle the elastomeric composition before curing starts. Thescorch time of the samples was tested using a cure rheometer(Oscillating Disk Rheometer (ODR)) and was performed according to ASTM D2084. As used herein, “ts2” is the time it takes for the torque of therheometer to increase 2 units above the minimum value and “tc90” is thetime to it takes to reach 90 weight percent of the difference betweenminimum to maximum torque. In another embodiment, the uncuredelastomeric composition exhibits a cure time of not more than about 15,14, 13, 12, 11, or 10 tc90, min. A shorter cure time indicates improvedprocessability because the elastomeric compositions can be cured at afaster rate, thus increasing production.

In certain embodiments, the cured elastomeric composition exhibits aDynamic Mechanical Analysis (“DMA”) strain sweep modulus as measured at5% strain and 30° C. of at least about 1,400,000, 1,450,000, 1,500,000,1,600,000, 1,700,000, or 1,800,000 Pa. A higher DMA strain sweep modulusindicates a higher modulus/hardness. The DMA Strain Sweep is testedusing a Metravib DMA150 dynamic mechanical analyzer under 0.001 to 0.5dynamic strain at 13 points in evenly spaced log steps at 30° C. and 10Hz.

In certain embodiments, the cured elastomeric composition exhibits amolded groove tear as measured according to ASTM D624 of at least about120, 125, 130, 140, 150, 155, 160, 165, or 170 lbf/in.

In certain embodiments, the cured elastomeric composition exhibits apeel tear as measured according to ASTM D1876-01 of at least about 80,85, 90, 95, 100, 110, 120, or 130 lbf/in.

In certain embodiments, the cured elastomeric composition exhibits abreak strain as measured according to ASTM D412 of at least about 360,380, 400, 420, 425, or 430 percent. In another embodiment, the curedelastomer composition exhibits a break stress as measured according toASTM D412 of at least 2,600, 2,800, 2,900, or 3,000 psi. The breakstrain and break stress are both indicators of the toughness andstiffness of the elastomeric compositions.

In certain embodiments, the cured elastomeric composition exhibits a tandelta at 0° C. and 5% strain in tension of not more than about 0.100,0.105, 0.110, or 0.115. In another embodiment, the cured elastomericcomposition exhibits a tan delta at 30° C. and 5% strain in shear of notmore than about 0.25, 0.24, 0.23, 0.22, or 0.21. The tan deltas weremeasured using a TA Instruments dynamic mechanical analyzer to completetemperature sweeps using tensile geometry. The tan deltas (=E″/E′)(storage modulus (E′) and loss modulus (E″)) were measured as a functionof temperature from −80° C. to 120° C. using 10 Hz frequency, 5% static,and 0.2% dynamic strain.

In certain embodiments, the cured elastomeric composition exhibits anadhesion strength at 100° C. of at least about 30, 35, 40, or 45 lbf/in.The adhesion strength at 100° C. is measured using 180-degree T-peelgeometry.

In certain embodiments, the cured elastomeric composition exhibits aShore A hardness of at least about 51, 53, 55, or 57. The Shore Ahardness is measured according to ASTM D2240.

(G) Products Incorporating the Elastomeric Compositions

The elastomeric compositions of the present invention can beincorporated into various types of articles.

In certain embodiments, the elastomeric composition is formed into atire and/or a tire component. The tire component can comprise, forexample, tire tread, subtread, undertread, body plies, belts, overlaycap plies, belt wedges, shoulder inserts, tire apex, tire sidewalls,bead fillers, and any other tire component that contains an elastomer.In one embodiment, the elastomeric composition is formed into tiretread, tire sidewalls, and/or bead fillers.

In certain embodiments, the elastomeric composition is incorporated intonon-tire applications. Non-tire applications include, for example, ablow-out preventer, fire hoses, weather stripping, belts, injectionmolded parts, footwear, pharmaceutical closures, plant lining, flooring,power cables, gaskets, seals, and architectural trims. In particular,the elastomeric compositions can be utilized in various oil fieldapplications such as, for example, blowout preventers, pump pistons,well head seals, valve seals, drilling hoses, pump stators, drill pipeprotectors, down-hole packers, inflatable packers, drill motors,O-Rings, cable jackets, pressure accumulators, swab cups, and bondedseals.

This invention can be further illustrated by the following examples ofpreferred embodiments thereof, although it will be understood that theseexamples are included merely for purposes of illustration and are notintended to limit the scope of the invention unless otherwisespecifically indicated.

EXAMPLES Example 1

Elastomeric compositions containing varying amounts of cellulose esterwere compared to elastomeric compositions not containing any celluloseester. The elastomeric compositions were produced according to theformulations and parameters in TABLE 1. Examples 1 and 2 containedvarying amounts of cellulose ester, while no cellulose ester was addedto Comparative Examples 1 and 2.

TABLE 1 Example Example Comparative Comparative Ingredient Component 1 2Example 1 Example 2 STAGE 1 BUNA VSL S-SBR 89.38 89.38 89.38 89.385025-2 HM extended with 37.5 phr TDAE BUNA CB 22 PBD Rubber 35 35 35 35ULTRASIL Silica 65 65 65 65 7000 GR N234 Carbon black 15 15 15 15 Si 266Coupling agent 5.08 5.08 5.08 5.08 SUNDEX 790 Aromatic oil — — — 8.75Stearic acid Cure Activator 1.5 1.5 1.5 1.5 Product of MB1 210.96 210.96210.96 219.71 Stage 1 STAGE 2 Product of MB1 210.96 210.96 210.96 219.71Stage 1 CAB-551-0.01 Cellulose Ester 7 15 — — Si 69 Coupling agent 0.5461.17 — — Zinc oxide Cure activator 1.9 1.9 1.9 1.9 OKERINMicrocrystalline 1.5 1.5 1.5 1.5 WAX 7240 wax SANTOFLEX Antioxidant 2 22 2 6PPD Product of MB2 223.91 232.53 216.36 225.11 Stage 2 STAGE 3Product of MB2 223.91 232.53 216.36 225.11 Stage 2 Sulfur Cross-linker1.28 1.28 1.28 1.28 SANTOCURE Accelerator 1.1 1.1 1.1 1.1 CBS PERKACITAccelerator 1.28 1.28 1.28 1.28 DPG-grs TOTAL 227.57 236.19 220.02228.77

The elastomeric compositions were prepared by first blending a solutionof styrene-butadiene rubber extended with 37.5 phr of TDAE oil (Buna VSL5025-2 HM from Lanxess, Cologne, Germany), a polybutadiene rubber (BunaC 22 from Lanxess, Cologne, Germany); silica, carbon black, a couplingagent (Si 266), and a cure activator (i.e., stearic acid) in a Banburymixer to create a first masterbatch. In addition, aromatic processingoil (Sundex® 790 from Petronas Lubricants, Belgium) was added to thefirst masterbatch used to produce Comparative Example 2. The firstmasterbatches were blended and produced according to the parameterslisted in Stage 1 of TABLES 1 and 2.

The first masterbatch for all examples was subsequently blended with acure activator, a microcrystalline wax, and an antioxidant to produce asecond masterbatch. Additionally, a cellulose ester (CAB-551-0.01 fromEastman Chemical Kingsport, Tenn.) and a coupling agent (SI 69 fromEvonik Degussa, Koln, Germany) were added to the first masterbatchesused to produce Examples 1 and 2. The second masterbatches were blendedand produced according to the parameters listed in Stage 2 of TABLES 1and 2.

The second masterbatch for all examples was blended with a crosslinkerand two different accelerators (Santocure® CBS and Perkacit® DPG-grsfrom Solutia, St. Louis, Mo.). The second masterbatches were processedaccording to the parameters listed in Stage 3 of TABLES 1 and 2. Afterprocessing, the second masterbatches were cured for 30 minutes at 160°C.

TABLE 2 STAGE 1 STAGE 2 STAGE 3 Start 65° C. 65° C. 50° C. TemperatureStarting Rotor 65 65 60 Speed (RPM) Fill Factor 67% 64% 61% Ram Pressure50 50 50 Mix Sequence Add primary elastomers Add half of first masterbatch Add half of second master After 1 minute, add 2/3 silica + After15 seconds, add other batch Si266 components and other half of firstmaster batch After 2 minutes, add 1/3 silica + After 1 minute, sweepAfter 15 seconds, add sulfur, other components accelerator package, andother half of second master batch After 3 minutes, sweep After 1.5minutes, adjust rotor After 1 minute, sweep After 3.5 minutes, adjustrotor speed to increase temperature speed to increase temperature to150° C. to 160° C. Dump Conditions Hold for 2 minutes at 160° C. Holdfor 4 minutes at 150° C. Hold for 2.5 minutes at 110° C. Total Time 6.5minutes 7.5 minutes 3.75 minutes

Example 2

Various performance properties of the elastomeric compositions producedin Example 1 were tested.

The break stress and break strain were measured as per ASTM D412 using aDie C for specimen preparation. The specimen had a width of 1 inch and alength of 4.5 inches. The speed of testing was 20 inches/min and thegauge length was 63.5 mm (2.5 inch). The samples were conditioned in thelab for 40 hours at 50%+/−5% humidity and at 72° F. (22° C.).

The Mooney Viscosities were measured at 100° C. according to ASTM D1646.

The Phillips Dispersion Rating was calculated by cutting the sampleswith a razor blade and subsequently taking pictures at 30× magnificationwith an Olympus SZ60 Zoom Stereo Microscope interfaced with a PAXCAM ARCdigital camera and a Hewlett Packard 4600 color printer. The pictures ofthe samples were then compared to a Phillips standard dispersion ratingchart having standards ranging from 1 (bad) to 10 (excellent).

The Dynamic Mechanical Analysis (“DMA”) Strain Sweep was tested using aMetravib DMA150 Dynamic Mechanical Analyzer in shear deformation toperform a double strain sweep experiment that utilized a simple shear of10 mm×2 mm. The experimental conditions were 0.001 to 0.5 dynamic strainat 13 points in evenly spaced log steps at 30° C. and 10 Hz.

The Hot Molded Groove Trouser Tear was measured at 100° C. according toASTM test method D624.

The Peel Tear (adhesion to self at 100° C.) was measured using 180°T-peel geometry and according to ASTM test method D1876-01 with amodification. The standard 1″×6″ peel test piece was modified to reducethe adhesion test area with a Mylar window. The window size was3″×0.125″ and the pull rate was 2″/min.

The results of these tests are depicted in TABLE 3 for each elastomericcomposition. TABLE 3 shows that the addition of cellulose esters andaromatic processing oils can reduce the Mooney Viscosity of theelastomeric composition, thus indicating better processability.Comparative Example 1, which did not contain either component, exhibiteda high Mooney Viscosity, thus indicating poorer processability. Further,the addition cellulose esters increased the DMA Strain Sweep, thus theseelastomeric compositions exhibited improved hardness and handlingproperties. In contrast, Comparative Example 2, which utilized anaromatic processing oil to lower its Mooney Viscosity, exhibited a lowDMA Strain Sweep. Thus, while the aromatic processing oil led to adecrease in the Mooney Viscosity, it resulted in an undesirable decreasein the elastomeric composition's handling and hardness properties.Moreover, elastomeric compositions containing cellulose esters exhibiteda higher tear strength, as depicted by the molded groove tear and peeltear at 100° C., relative to the comparative examples. Furthermore,TABLE 3 shows that the addition of an aromatic processing oil, like inComparative Example 2, had little to no impact on tear strength.

TABLE 3 DMA Strain Molded Break Mooney Phillips Sweep (5% Groove TearPeel Tear at Stress Break viscosity Dispersion strain in shear) at 100°C. 100° C. Sample (psi) Strain % (AU) Rating (Pa) (lbf/in) (lbf/in)Example 1 3031 432 90.9 7 1740000 172 102 Example 2 3017 447 88.4 61830000 160 135 Comparative Example 1 2915 358 98.1 6 1680000 126 81.1Comparative Example 2 2785 405 83.7 5 1400000 123 94

Example 3

In this example, elastomeric compositions were produced using themasterbatch process. A number of different cellulose ester concentrateswere prepared and subsequently combined with elastomers to produce theelastomeric compositions.

In the first stage of the masterbatch process, cellulose esters were bagblended with styrenic block copolymer materials and then fed using asimple volumetric feeder into the chilled feed throat of a Leitstritztwin screw extruder to make cellulose ester concentrates (i.e.,masterbatches). The various properties of the cellulose esters andstyrenic block copolymer materials utilized in this first stage aredepicted in TABLES 4 and 5. All of the recited cellulose esters in TABLE4 are from Eastman Chemical Company, Kingsport, Tenn. All of thestyrenic block copolymers in TABLE 5 are from Kraton Polymers, Houston,Tex. The Leistritz extruder is an 18 mm diameter counter-rotatingextruder having an L/D of 38:1. Material was typically extruded at 300to 350 RPM with a volumetric feed rate that maintained a screw torquevalue greater than 50 weight percent. Samples were extruded through astrand die, and quenched in a water bath, prior to being pelletized.Relative loading levels of cellulose esters and styrenic blockcopolymers were varied to determine affect on mixing efficiency.

In the second stage, these cellulose ester concentrates were mixed witha base rubber formulation using a Brabender batch mixer equipped withroller type high shear blades. The base rubber was a blend of a styrenebutadiene rubber (Buna 5025-2, 89.4 pph) and polybutadiene rubber (BunaCB24, 35 pph). Mixing was performed at a set temperature of 160° C. anda starting rotor speed of 50 RPM. RPM was decreased as needed tominimize overheating due to excessive shear. The cellulose esterconcentrate loading level was adjusted so that there was about 20 weightpercent cellulose ester in the final mix.

For the Comparative Examples, cellulose ester and plasticizer (i.e., norubber) were first combined together in a Brabender batch mixer equippedwith roller high shear blades in order to form a masterbatch.Plasticizer was added to enhance flow and lower viscosity as it has beenobserved that high viscosity cellulose esters will not mix at theprocessing temperature of the rubber (i.e., 150 to 160° C.). Mixing wasperformed for approximately 10 to 15 minutes at 160° C. and 50 RPM. Uponcompletion, the sample was removed and cryo-ground to form a powder.

In the next stage, 20 weight percent of the cellulose ester/plasticizermasterbatch was added to the rubber formulation using the same Brabendermixer at 160° C. and 50 RPM. The masterbatch was added 30 seconds afterthe rubber compound had been fully introduced into the mixer. Mixing wasperformed for approximately 10 minutes after all ingredients had beenadded. The sample was then removed and tested.

The particle sizes in the dispersion were measured using a compoundlight microscope (typically 40×). The samples could be cryo-polished toimprove image quality and the microscope could run in differentialinterference contrast mode to enhance contrast.

The glass transition temperatures were measured using a DSC with ascanning rate of 20° C./minute.

The base formulations for all samples tested and produced as describedbelow are depicted in TABLES 6A, 6B, and 6C.

TABLE 4 Falling Ball Tg Melting Grade Type Viscosity (° C.) Range(° C.)CAB 381-0.1 Cellulose acetate 0.1 123 155-165 butyrate CAB 381-0.5Cellulose acetate 0.5 130 155-165 butyrate CAB 381-2 Cellulose acetate 2133 171-184 butyrate CAB 381-6 Cellulose acetate 6 135 184 to 190butyrate (est) (est) CAB 381-20 Cellulose acetate 6 141 195-204 butyrateCAP 482-0.5 Cellulose acetate 0.5 142 188-210 propionate CAP 482-2Cellulose acetate 2 143 188-210 propionate CAP 482-6 Cellulose acetate 6144 188-210 propionate (est) (est) CAP 482-20 Cellulose acetate 6 147188-210 propionate CA 398-30 Cellulose acetate 30 180 230-250

TABLE 5 MI @ Diblock Shore MA Grade Type Styrene 200° C. contentHardness bound D1118KT Diblock styrene/ 33 wt % 10 78 74 Na butadieneD1102KT Triblock styrene/ 28 wt % 14 17 66 Na butadiene D1101KT Triblockstyrene/ 31 wt % <1 16 wt % 69 Na butadiene FG1924GT Triblock, 13 wt %40 @ na 49 0.7 to 1.3 wt % styrene ethylene/ 230° C. butylene FG1901GTriblock, 30 wt % 22 @ na 71 1.4 to 2.0 wt % styrene ethylene/ 230° C.butylene

Example 3(a)

In this example, a cellulose ester concentrate was produced thatcontained 40 weight percent of Eastman CAB 381-0.1 and 60 weight percentof Kraton FG1924. The materials were compounded using a medium shearscrew design at max zone temperatures of 200° C. and a residence time ofless than one minute. The cellulose ester concentrate was combined withthe base rubber formulation at a 50:50 weight ratio and mixed in aBrabender mixer. The final elastomeric composition contained 50 weightpercent of base rubber, 30 weight percent of Kraton FG 1924, and 20weight percent of CAB 381-0.1. The particles were evenly dispersed andhad particle sizes of less than 1 micron.

Example 3(b)

In this example, a cellulose ester concentrate was produced thatcontained 60 weight percent of Eastman CAB 381-0.1 and 40 weight percentof Kraton FG1924. The materials were compounded using a medium shearscrew design at max zone temperatures of 200° C. and a residence timeless of than one minute. The cellulose ester concentrate was combinedwith the base rubber formulation at a 33.3/66.7 weight ratio and mixedin a Brabender mixer. The final formulation contained 66.7 weightpercent of the base rubber, 13.3 weight percent of Kraton FG 1924, and20 weight percent of CAB 381-0.1. The particles were evenly dispersedand had particle sizes of less than 3 microns, with most particles beingless than 1 micron.

Example 3(c)

In this example, a cellulose ester concentrate was produced thatcontained 40 weight percent of Eastman CAB 381-0.5 and 60 weight percentof Kraton FG1924. The materials were compounded using a medium shearscrew design at max zone temperatures of 225° C. and a residence time ofless than one minute. The cellulose ester concentrate was combined withthe base rubber formulation at a 50/50 weight ratio and mixed in aBrabender mixer. The final formulation contained 50 weight percent ofbase rubber, 30 weight percent of Kraton FG 1924, and 20 weight percentof CAB 381-0.5. The particles were evenly dispersed and had a particlesize less than 1 micron.

Example 3(d)

In this example, a cellulose ester concentrate was produced thatcontained 40 weight percent of Eastman CAB 381-2 and 60 weight percentof Kraton FG1924. The materials were compounded using a medium shearscrew design at max zone temperatures of 250° C. and a residence time ofless than one minute. The cellulose ester concentrate was combined withthe base rubber formulation at a 50/50 weight ratio and mixed in aBrabender mixer. The final formulation contained 50 weight percent ofbase rubber, 30 weight percent of Kraton FG 1924, and 20 weight percentof CAB 381-2. The particles were evenly dispersed and had particle sizesof less than 1 micron.

Example 3(e)

In this example, a cellulose ester concentrate was produced thatcontained 40 weight percent of Eastman CAB 381-0.1 and 60 weight percentof Kraton D1102. The materials were compounded using a medium shearscrew design at max zone temperatures of 200° C. and a residence time ofless than one minute. The cellulose ester concentrate was combined withthe base rubber formulation at a 50/50 weight ratio and mixed in aBrabender mixer. The final formulation contained 50 weight percent ofbase rubber, 30 weight percent of Kraton D1102, and 20 weight percent ofCAB 381-0.1. The particles were evenly dispersed and had particle sizesof less than 3 microns.

Example 3(f)

In this example, a cellulose ester concentrate was produced thatcontained 40 weight percent of Eastman CAB 381-0.1 and 60 weight percentof Kraton D1101. The materials were compounded using a medium shearscrew design at max zone temperatures of 200° C. and a residence time ofless than one minute. The cellulose ester concentrate was combined withthe base rubber formulation at a 50/50 weight ratio and mixed in aBrabender mixer. The final formulation contained 50 weight percent ofbase rubber, 30 weight percent of Kraton D1101, and 20 weight percent ofCAB 381-0.1. The particles were evenly dispersed and had particle sizesof less than 5 microns.

Example 3(g)

In this example, a cellulose ester concentrate was produced thatcontained 40 weight percent of Eastman CAB 381-0.1 and 60 weight percentof Kraton D1118. The materials were compounded using a medium shearscrew design at max zone temperatures of 200° C. and a residence time ofless than one minute. The cellulose ester concentrate was combined withthe base rubber formulation at a 50/50 weight ratio and mixed in aBrabender mixer. The final formulation contained 50 weight percent ofbase rubber, 30 weight percent of Kraton D1118, and 20 weight percent ofCAB 381-0.1. The particles were evenly dispersed and had particle sizesless than 3 microns.

Example 3(h)

In this example, a cellulose ester concentrate was produced thatcontained 40 weight percent of Eastman CAP 482-0.5 and 60 weight percentof Kraton FG 1924. The materials were compounded using a medium shearscrew design at max zone temperatures of 250° C. and a residence time ofless than one minute. The cellulose ester concentrate was combined withthe base rubber formulation at a 50/50 weight ratio and mixed in aBrabender mixer. The final formulation contained 50 weight percent ofbase rubber, 30 weight percent of Kraton FG 1924, and 20 weight percentof CAP 482-0.5. The particles were evenly dispersed and had particlesizes of less than 1 micron.

Example 3(i)

In this example, a cellulose ester concentrate was produced thatcontained 40 weight percent of Eastman CA 398-3 and 60 weight percent ofKraton FG 1924. The materials were compounded using a medium shear screwdesign at max zone temperatures of 250° C. and a residence time of lessthan one minute. The cellulose ester concentrate was combined with thebase rubber formulation at a 50/50 weight ratio and mixed in a Brabendermixer. The final formulation contained 50 weight percent of base rubber,30 weight percent of Kraton FG 1924, and 20 weight percent of CA 398-3.The particles were evenly dispersed and had particle sizes less than 3microns.

Example 3(j)

In this example, a cellulose ester concentrate was produced thatcontained 40 weight of percent Eastman CAB 381-0.1 and 60 weight percentof Kraton FG1901. The materials were compounded using a medium shearscrew design at max zone temperatures of 200° C. and a residence time ofless than one minute. The cellulose ester concentrate was combined withthe base rubber formulation at a 50/50 weight ratio and mixed in aBrabender mixer. The final formulation contained 50 weight percent ofbase rubber, 30 weight percent of Kraton FG 1901, and 20 weight percentof CAB 381-0.1. The particles were evenly dispersed and had particlesizes of less than 1 micron.

Example 3(k)

In this example, a cellulose ester concentrate was produced thatcontained 40 weight percent of Eastman CAB 381-0.5 and 60 weight percentof Kraton FG1901. The materials were compounded using a medium shearscrew design at max zone temperatures of 225° C. and a residence time ofless than one minute. The cellulose ester concentrate was combined withthe base rubber formulation at a 50/50 weight ratio and mixed in aBrabender mixer. The final formulation contained 50 weight percent ofbase rubber, 30 weight percent Kraton FG 1901, and 20 weight percent ofCAB 381-0.5. The particles were evenly dispersed and had particle sizesof less than 1 micron.

Example 3(l)

In this example, a cellulose ester concentrate was produced thatcontained 40 weight percent of Eastman CAB 381-2 and 60 weight percentof Kraton FG1901. The materials were compounded using a medium shearscrew design at max zone temperatures of 250° C. and a residence time ofless than one minute. The cellulose ester concentrate was combined withthe base rubber formulation at a 50/50 weight ratio and mixed in aBrabender mixer. The final formulation contained 50 weight percent ofbase rubber, 30 weight percent of Kraton FG 1901, and 20 weight percentof CAB 381-2. The particles were evenly dispersed and had particle sizesof less than 1 micron.

Example 3(m)

In this example, a cellulose ester concentrate was produced thatcontained 40 weight percent of Eastman CAP 482-0.5 and 60 weight percentof Kraton FG1901. The materials were compounded using a medium shearscrew design at max zone temperatures of 250° C. and a residence time ofless than one minute. The cellulose ester concentrate was combined withthe base rubber formulation at a 50/50 weight ratio and mixed in aBrabender mixer. The final formulation contained 50 weight percent ofbase rubber, 30 weight percent of Kraton FG 1901, and 20 weight percentof CAP 482-0.5. The particles were evenly dispersed and had particlesizes of less than 3 microns.

Example 3(n)

In this example, a cellulose ester concentrate was produced thatcontained 40 weight percent of Eastman CA 398-3 and 60 weight percent ofKraton FG 1901. The materials were compounded using a medium shear screwdesign at max zone temperatures of 250° C. and a residence time of lessthan one minute. The cellulose ester concentrate was combined with thebase rubber formulation at a 50/50 weight ratio and mixed in a Brabendermixer. The final formulation contained 50 weight percent of base rubber,30 weight percent of Kraton FG 1901, and 20 weight percent of CA 398-3.The particles were evenly dispersed and had particle sizes of less than1 micron.

Example 3(o)

In this example, 67 weight percent of Eastman CAB 381-20 was meltblended with 33 weight percent of Eastman CAB 381-0.5 to produce anestimated CAB 381-6 material having a falling ball viscosity of 6.Subsequently, 40 weight percent of this cellulose ester blend was meltblended with 60 weight percent of Kraton FG 1924. The materials werecompounded using a medium shear screw design at max zone temperatures of200° C. and a residence time of less than one minute. The celluloseester concentrate was combined with the base rubber formulation at a50/50 weight ratio and mixed in a Brabender mixer. The final formulationcontained 50 weight percent of base rubber, 30 weight percent of KratonFG 1924, and 20 weight percent of CAB 381-6. The particles were evenlydispersed and had particle sizes of less than 3 microns.

Example 3(p)

In this example, 67 weight percent of Eastman CAP 482-20 was meltblended with 33 weight percent of Eastman CAP 482-0.5 to produce anestimated CAP 482-6 material. Subsequently, 40 weight percent of thiscellulose ester blend was melt blended with 60 weight percent of KratonFG 1924. The materials were compounded using a medium shear screw designat max zone temperatures of 200° C. and a residence time of less thanone minute. The cellulose ester concentrate was combined with the baserubber formulation at a 50/50 weight ratio and mixed in a Brabendermixer. The final formulation contained 50 weight percent of base rubber,30 weight percent of Kraton FG 1924, and 20 weight percent of CAP 482-6.The particles were evenly dispersed and had particle sizes of less than1 micron.

Example 3(q)

In this example, 67 weight percent of Eastman CAP 482-20 was meltblended with 33 weight percent of Eastman CAP 482-0.5 to produce anestimated CAP 482-6 material. Subsequently, 40 weight percent of thiscellulose ester blend was melt blended with 60 weight percent of KratonD1102. The materials were compounded using a medium shear screw designat max zone temperatures of 200° C. and a residence time of less thanone minute. The cellulose ester concentrate was combined with the baserubber formulation at a 50/50 weight ratio and mixed in a Brabendermixer. The final formulation contained 50 weight percent of base rubber,30 weight percent of Kraton D1102, and 20 weight percent of CAP 482-6.The particles were evenly dispersed and had particle sizes of less than5 microns.

Example 3(r)

In this example, 90 weight percent of Eastman CA 398-3 was melt blendedwith 10 weight percent of triphenyl phosphate to produce a plasticizedcellulose acetate pre-blend. Subsequently, 40 weight percent of thisplasticized cellulose acetate was melt blended with 60 weight percentKraton D1102. The materials were compounded using a medium shear screwdesign at max zone temperatures of 200° C. and a residence time of lessthan one minute. The cellulose ester concentrate was combined with thebase rubber formulation at a 66.7/33.3 weight ratio and mixed in aBrabender mixer. The final formulation contained 33.3 weight percent ofbase rubber, 40 weight percent of Kraton D1102, 20 weight percent of CA398-3, and 6.67 weight percent triphenyl phosphate. The particles wereevenly dispersed and had particle sizes of less than 3 microns.

Example 3(s)

In this example, 90 weight percent of Eastman CA 398-3 was melt blendedwith 10 weight percent of triphenyl phosphate to produce a plasticizedcellulose acetate pre-blend. Subsequently, 40 weight percent of thisplasticized cellulose acetate was melt blended with 60 weight percent ofKraton FG 1924. The materials were compounded using a medium shear screwdesign at max zone temperatures of 200° C. and a residence time of lessthan one minute. The cellulose ester concentrate was combined with thebase rubber formulation at a 66.7/33.3 weight ratio and mixed in aBrabender mixer. The final formulation contained 33.3 weight percent ofbase rubber, 40 weight percent of Kraton FG 1924, 20 weight percent ofCA 398-3, and 6.67 weight percent of triphenyl phosphate. The particleswere evenly dispersed and had particle sizes of less than 1 micron.

Comparative Example 3(a)

In this example, a masterbatch was produced having 90 weight percent ofEastman CAB 381-0.1 and 10 weight percent of dioctyl adipateplasticizer. The CAB had a falling ball viscosity of 0.1 and the mixturehad an estimated Tg of 95° C. The masterbatch was combined with the baserubber formulation at a 20/80 weight ratio and mixed in a Brabendermixer. This was done to simulate “direct mixing” as is currentlypracticed in the art. Most of the particles were evenly dispersed andhad sizes predominantly between 5 and 10 microns; however, a fewparticles showed clustering in the 25 microns range.

Comparative Example 3(b)

Following the same procedure as in Comparative Example 3(a), an attemptwas made to mix Eastman CA 398-3 powder without plasticizer into therubber formulation. The CA had a falling ball viscosity of 3 and a Tg ofapproximately 180° C. Mixing could not be performed because the CA wouldnot soften at the mixing temperature of 160° C.

Comparative Example 3(c)

Following the same procedure as in Comparative Example 3(a), amasterbatch was produced from a 50/50 mix of Eastman CA 398-3 andpolyethylene glycol plasticizer. The high level of plasticizer wasrequired in order to make the CA processable at 160° C. The Tg of themixture was estimated to be less than 100° C. Particles partiallydispersed but overall quality was poor with large clumps of celluloseacetate being present having particle sizes greater than 25 microns.

Comparative Example 3(d)

Following the same procedure as in Comparative Example 3(a), amasterbatch was produced from a 75/25 mix of Eastman CAP 482-0.5 anddioctyl adipate plasticizer. The high level of plasticizer was requiredin order to make the CAP processable at 160° C. The Tg of the mixturewas estimated to be less than 100° C. Particles partially dispersed butoverall quality was poor with large clumps of cellulose acetatepropionate being present having particle sizes greater than 25 microns.

Comparative Example 3(e)

Following the same procedure as in Comparative Example 3(a), amasterbatch was produced from a 80/20 mix of Eastman CAP 482-0.5 andpolyethylene glycol plasticizer. The high level of plasticizer wasrequired in order to make the CAP processable at 160° C. The Tg of themixture was estimated to be less than 100° C. Particles dispersed fairlywell with most particles having sizes predominantly between 5 and 15microns.

TABLE 6A Example Example Example Example Example Example Example ExampleExample Example Example 3(a) 3(b) 3(c) 3(d) 3(e) 3(f) 3(g) 3(h) 3(i)3(j) 3(k) Cellulose Ester Concentrate Formulations Cellulose Ester 40 6040 40 40 40 40 40 40 40 40 Carrier Elastomer 60 40 60 60 60 60 60 60 6060 60 Plasticizer — — — — — — — — — — — CE Concentrate 100 100 100 100100 100 100 100 100 100 100 (Total wt %) Mixing Ratios for ElastomericCompositions Base Rubber 50 66.7 50 50 50 50 50 50 50 50 50 CEConcentrate 50 33.3 50 50 50 50 50 50 50 50 50 Elastomeric 100 100 100100 100 100 100 100 100 100 100 Composition (Total wt %) FinalFormulations of Produced Elastomeric Compositions Cellulose Ester 20 2020 20 20 20 20 20 20 20 20 Carrier Elastomer 30 13.3 30 30 30 30 30 3030 30 30 Base Rubber 50 66.7 50 50 50 50 50 50 50 50 50 Dispersion <1 μm<1 μm <1 μm <1 μm <3 μm <5 μm <3 μm <1 μm <3 μm <1 μm <1 μm ParticleSize

TABLE 6B Comparative Comparative Example Example Example Example ExampleExample Example Example Example Example 3(l) 3(m) 3(n) 3(o) 3(p) 3(q)3(r) 3(s) 3(a) 3(b) Cellulose Ester Concentrate Formulations Cellulose40 40 40 40 40 40 36 36 90 — Ester Carrier 60 60 60 60 60 60 60 60 — —Elastomer Plasticizer — — — — — — 4 4 — CE 100 100 100 100 100 100 100100 100 — Concentrate (Total wt %) Mixing Ratios for ElastomericCompositions Base 50 50 50 50 50 50 33.3 33.3 80 — Rubber CE 50 50 50 5050 50 66.7 66.7 20 — Concentrate Elastomeric 100 100 100 100 100 100 100100 100 — Composition (Total wt %) Final Formulations of ProducedElastomeric Compositions Cellulose 20 20 20 20 20 20 20 20 18 — EsterCarrier 30 30 30 30 30 30 40 40 — — Elastomer Base 50 50 50 50 50 5033.3 33.3 80 — Rubber Plasticizer — — — — — — 6.67 6.67 2 — Dispersion<1 μm <3 μm <1 μm <3 μm <1 μm <5 μm <3 μm <1 μm 5-10 μm — Particle Size

TABLE 6C Comparative Comparative Comparative Example 3(c) Example 3(d)Example 3(e) Cellulose Ester Concentrate Formulations Cellulose 50 75 80Ester Carrier — — — Elastomer Plasticizer 50 25 20 CE 100 100 100Concentrate (Total wt %) Mixing Ratios for Elastomeric Compositions Base80 80 80 Rubber CE 20 20 20 Concentrate Elastomeric 100 100 100Composition (Total wt %) Final Formulations of Produced ElastomericCompositions Cellulose 10 15 16 Ester Carrier — — — Elastomer Base 80 8080 Rubber Plasticizer 10 5 4 Dispersion >25 μm >25 μm 10-15 μm ParticleSize

Example 4

This example shows the advantages of using modified cellulose esterswith plasticizers in tire formulations compared to using only celluloseesters. TABLE 7 shows the tire formulations that were produced. TABLE 8shows the cellulose ester/plasticizer masterbatch formulations that wereproduced. The elastomeric compositions were produced using the procedureparameters outlined in TABLES 7 and 9.

TABLE 9 depicts the mixing conditions of the three stages. Thecomponents were mixed in a Banbury mixer. After preparing theelastomeric compositions, the composition was cured for T90+5 minutes at160° C.

TABLE 7 Ingredient Component CAB-1 CAB-2 CAB-3 STAGE 1 Buna VSL S-SBR103.12 103.12 103.12 5025-2 extended with 37.5 phr TDAE Buna CB24 PBDRubber 25 25 25 Rhodia 1165 Silica 70 70 70 MP N234 Carbon black 15 1515 Si69 Coupling agent 5.47 5.47 5.47 Sundex ® 790 Aromatic oil 5 5 5Stearic acid Cure Activator 1.5 1.5 1.5 Product of MB1 210.9 210.9 210.9Stage 1 STAGE 2 Product of MB1 210.9 210.9 210.9 Stage 1 CE/PlasticizerCE-MB1 10 — — Blends CE-MB2 — 12.5 — CE-MB3 — — 12.5 Si 69 Couplingagent 0.546 1.17 — Zinc oxide Cure activator 1.9 1.9 1.9 Okerin ® WaxMicrocrystalline 1.5 1.5 1.5 7240 wax Santoflex ® Antioxidant 2 2 2 6PPDStrutkol ® KK49 Processing Aid 2 2 2 Product of MB2 217.49 229.99 229.99Stage 2 STAGE 3 Product of MB2 217.49 229.99 229.99 Stage 2 SulfurCross-linker 1.5 1.5 1.5 Santocure ® Accelerator 1.3 1.3 1.3 CBSPerkacit ® Accelerator 1.5 1.5 1.5 DPG-grs TOTAL 221.79 234.29 234.29

TABLE 8 CE/ Pz level Phr of MB Tg after Plasticizer Tg before (g/100 gin formu- plasti- Blends CE plasticizer Plasticizer CE) lation cizerCE-MB1 CAB 133° C. — — 10 133° C. 381-2 CE-MB2 CAB 133° C. EMN 168 2512.5  95° C. 381-2 CE-MB3 CAB 133° C. PEG-300 25 12.5  70° C. 381-2

TABLE 9 STAGE 1 STAGE 2 STAGE 3 Start Temperature 65° C. 65° C. 50° C.Starting Rotor 65 65 60 Speed (RPM) Fill Factor 67% 64% 61% Mix SequenceAdd elastomers Add half of first master batch Add half of second After 1minute, add 2/3 silica + After 15 seconds, add other master batch Si69components and other half of first master batch After 2 minutes, add 1/3silica + After 1 minute, sweep After 15 seconds, add other componentssulfur, accelerator After 3 minutes, sweep After 1.5 minutes, adjustrotor package, and other half of After 3.5 minutes, adjust rotor speedto increase temperature second master batch speed to increase to between140 and 145° C. After 1 minute, sweep temperature to 160° C. DumpConditions Hold for 2 minutes at 160° C. Hold for 4 minutes at Hold for2.5 minutes at 140 to 145° C. 110° C. Total Time 6.5 minutes 7.5 minutes3.75 minutes

Example 5

Various performance properties of the elastomeric compositions producedin Example 4 were tested. Descriptions of the various analyticaltechniques used to measure performance are provided below.

The break stress and break strain were measured as per ASTM D412 using aDie C for specimen preparation. The specimen had a width of 1 inch and alength of 4.5 inches. The speed of testing was 20 inches/min and thegauge length was 63.5 mm (2.5 inch). The samples were conditioned in thelab for 40 hours at 50%+/−5% humidity and at 72° F. (22° C.).

The Mooney Viscosities were measured according to ASTM D 1646.

The Phillips Dispersion Rating was calculated by cutting the sampleswith a razor blade and subsequently taking pictures at 30× magnificationwith an Olympus SZ60 Zoom Stereo Microscope interfaced with a Paxcam Arcdigital camera and a Hewlett Packard 4600 color printer. The pictures ofthe samples were then compared to a Phillips standard dispersion ratingchart having standards ranging from 1 (bad) to 10 (excellent).

Mechanical Properties: modulus at 100% and 300% strains were measured asper ASTM D412 using Die C for specimen preparation. The speed of testingwas 20 inches/min and the gauge length was 63.5 mm (2.5 inch). Thesamples were conditioned in the lab for 40 hours at 50% +/−5 humidityand 72° F. The width of specimen was 1 inch, and length was 4.5 inch.

Hardness: Shore A hardness was measured according to ASTM D2240.

Temperature Sweep: A TA Instruments dynamic mechanical analyzer was usedto complete the temperature sweeps using tensile geometry. Storagemodulus (E′), loss modulus (E″), and tan delta (=E″/E′) were measured asa function of temperature from −80° C. to 120° C. using 10 Hz frequency,5% static, and 0.2% dynamic strain.

Rebound Test: The rebound pendulum test was carried out as per ASTMD7121-05.

Wear: Din abrasion testing was performed per ASTM 222.

The data shows that without the use of a plasticizer, the celluloseester did not disperse as well through the elastomer as shown by thepoor Phillips Dispersion data. Further, the Mooney Viscosities of thecompositions containing both cellulose ester and plasticizer were lowerthan when plasticizer was not utilized. This shows that in the presenceof the plasticizer, cellulose esters acted as a processing aid andlowered Mooney viscosity. Furthermore, the break stress and wear wasalso improved over compositions without plasticizer, presumablyindicating that in presence of the plasticizers, cellulose esters candisperse into finer particles and improve the properties that aredependent on particle size and/or surface area.

TABLE 10 Properties CAB-1 CAB-2 CAB-3 Uncured Rubber Mooney viscosity63.5 58.5 55.1 Cured Rubber Phillips Dispersion 1 4 4 Break stress, psi2191 2240 2349 Break strain, % 386 387 366 Modulus(M100), psi 663 679735 Modulus (M300), 1693 1723 1918 psi Shore A Hardness 61 59 62 TanDelta 0° C. 0.306 0.292 0.313 Tan Delta 60° C. 0.082 0.081 0.076 Rebound0° C., % 9.8 10.8 9.6 Rebound 60° C., % 62.2 62.8 64.0 Wear, volume loss136 124 127 in mm³

That which is claimed is:
 1. An elastomeric composition comprising atleast one non-fibril cellulose ester, at least one non-nitrile primaryelastomer, and at least 70 parts per hundred rubber (phr) of one or morefillers, wherein a starch is absent from said elastomeric composition;and wherein at least a portion of said at least one non-fibril celluloseester is dispersed in said at least one non-nitrile primary elastomer,wherein said at least one non-nitrile primary elastomer forms acontinuous phase and at least a portion of said at least one non-fibrilcellulose ester forms a dispersed phase; and wherein said elastomericcomposition exhibits a molded groove tear as measured according to ASTMD624 of at least 130 lbf/in.
 2. The elastomeric composition according toclaim 1 wherein said elastomeric composition comprises at least 1 andnot more than 75 phr of said at least one non-fibril cellulose ester. 3.The elastomeric composition according to claim 1 wherein saidelastomeric composition comprises at least 75 phr and/or not more than150 phr of said one or more fillers.
 4. The elastomeric compositionaccording to claim 1 wherein said elastomeric composition comprises atleast 85 phr and/or not more than 130 phr of said one or more fillers.5. The elastomeric composition according to claim 1 wherein said one ormore fillers comprise silica, carbon black, clay, alumina, talc, mica,discontinuous fibers including cellulose fibers and glass fibers,aluminum silicate, aluminum trihydrate, barites, feldspar, nepheline,antimony oxide, calcium carbonate, kaolin, and combinations thereof. 6.The elastomeric composition according to claim 1 wherein said at leastone non-fibril cellulose ester is in the form of particles having anaverage diameter of not more than 10 μm, wherein at least 75 percent ofsaid particles have an aspect ratio of not more than 2:1.
 7. Theelastomeric composition according to claim 1 wherein said at least onenon-fibril cellulose ester is in the form of particles having an averagediameter of not more than 10 μm, wherein at least 75 percent of saidparticles have a particle size of not more than 8 μm.
 8. The elastomericcomposition according to claim 1 wherein said elastomeric compositionexhibits a Mooney viscosity at 100° C. as measured according to ASTM D1646 of not more than 110 AU when uncured.
 9. The elastomericcomposition according to claim 1 wherein said elastomeric compositionexhibits a Mooney viscosity at 100° C. as measured according to ASTM D1646 of not more than 90 AU when uncured.
 10. The elastomericcomposition according to claim 1 wherein said elastomeric compositionexhibits a DMA strain sweep modulus as measured at 5% strain and 30° C.of at least 1,400,000 Pa.
 11. The elastomeric composition according toclaim 1 wherein said at least one non-fibril cellulose ester is selectedfrom the group consisting of cellulose acetate, cellulose acetatepropionate, cellulose acetate butyrate, cellulose triacetate, cellulosetripropionate, cellulose tributyrate, and mixtures thereof.
 12. Theelastomeric composition according to claim 1 wherein said at least onenon-nitrile primary elastomer is non-polar.
 13. The elastomericcomposition according to claim 1 wherein said at least one non-nitrileprimary elastomer is selected from the group consisting of naturalrubber, polybutadiene, polyisoprene, styrene-butadiene rubber,polyolefins, ethylene propylene diene monomer (EPDM), polynorbornene,and combinations thereof.
 14. The elastomeric composition according toclaim 1 wherein said at least one non-fibril cellulose ester is amodified cellulose ester that has been modified by at least oneplasticizer.
 15. The elastomeric composition according to claim 14wherein said at least one plasticizer forms at least 1 and not more than60 weight percent of said modified cellulose ester.
 16. The elastomericcomposition according to claim 14 wherein said at least one plasticizeris one selected from the group consisting of a phosphate plasticizer,benzoate plasticizer, adipate plasticizer, a phthalate plasticizer, aglycolic acid ester, a citric acid ester plasticizer, and ahydroxyl-functional plasticizer.
 17. The elastomeric compositionaccording to claim 14 wherein said at least one plasticizer is selectedfrom at least one of the following: triphenyl phosphate, tricresylphosphate, cresyldiphenyl phosphate, octyldiphenyl phosphate,diphenylbiphenyl phosphate, trioctyl phosphate, tributyl phosphate,diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctylphthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, butylbenzylphthalate, dibenzyl phthalate, butyl phthalyl butyl glycolate, ethylphthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, triethylcitrate, tri-n-butyl citrate, acetyltriethyl citrate, acetyl-tri-n-butylcitrate, and acetyl-tri-n-(2-ethylhexyl) citrate.
 18. An articlecomprising said elastomeric composition of claim
 1. 19. The articleaccording to claim 18 wherein said article comprises a tire.